Biochemistry

A previous study postulated that acetate metabolism was a metabolic sensory mechanism that related information about E. coli's environment to the formation of biofilms (Prüβ et al., Arch. Microbiol. 2010). Considering that mutants in pta ackA (no acetyl phosphate) and ackA (high acetyl phosphate) exhibited similarly increased biofilm amounts and three dimensional structures, the hypothesis for this study was that acetyl Co-A was a more likely mediator of the acetate effect than acetyl phosphate. The effect of acetate metabolism on biofilm amounts was detailed by using single carbon sources rather than the previously used mixed amino acid medium, as well as mutations in additional genes that contribute to acetate metabolism (ldhA, pflA, pflB). In summary, the mutations in ackA, pta ackA, and ldhA increased biofilm amounts in the presence of maltose, D-trehalose, D-mannose, and L-rhamnose, all of which get converted to acetyl-CoA. The ackA mutant also exhibited increased biofilm a...

Coronavirus disease-19 (COVID-19) are deadly and infectious disease that impacts individuals in a variety of ways. Scientists have stepped up their attempts to find an antiviral drug that targets the spike protein (S) of Angiotensin converting enzyme 2 (ACE2) (receptor protein) as a viable therapeutic target for coronavirus. The most recent study examines the potential antagonistic effects of 17 phytochemicals present in the plant extraction of Euphorbia neriifolia on the anti-SARS-CoV-2 ACE2 protein. Computational techniques like molecular docking, absorption, distribution, metabolism, excretion, and toxicity (ADMET) investigations, and molecular dynamics (MD) simulation analysis were used to investigate the actions of these phytochemicals. The results of molecular docking studies showed that the control ligand (2-acetamido-2deoxy-β-D-glucopyranose) had a binding potential of -6.2 kcal/mol, but the binding potentials of delphin, β-amyrin, and tulipanin are greater at -10.4, 10.0, and -9.6 kcal/mol. To verify their drug-likeness, the discovered hits were put via Lipinski filters and ADMET analysis. According to MD simulations of the complex run for 100 numbers, delphin binds to the SARS-CoV-2 ACE2 receptor's active region with good stability. In root-mean-square deviation (RMSD) and root mean square fluctuation (RMSF) calculations, delphinan, β-amyrin, and tulipanin showed reduced variance with the receptor binding domain subunit 1(RBD S1) ACE2 protein complex. The solvent accessible surface area (SASA), radius of gyration (Rg), molecular surface area (MolSA), and polar surface area (PSA) validation results for these three compounds were likewise encouraging. The convenient binding energies across the 100 numbers binding period were discovered by using molecular mechanics of generalized born and surface (MM/GBSA) to estimate the ligand-binding free energies to the protein receptor. All things considered, the information points to a greater likelihood of chemicals found in Euphorbia neriifolia binding to the SARS-CoV-2 ACE2 active site. To determine these lead compounds' anti-SARS-CoV-2 potential, in vitro and in vivo studies should be conducted.

The compositional skills are analyzed to determine whether college students have improved their writing ability after the two years additional in the senior high school curriculum. This study examines the errors committed by first-year engineering students. There were 90 student respondents written outputs collected and subjected to Grammarly software. The researchers analyzed the data using the Scheffe test, comparing the difference between clarity, engagement, and delivery. Analysis of variance (ANOVA) was employed to test whether there is a significant difference among other variables. Findings revealed that clarity is the most common error committed by the student-respondents. The errors committed between male and female respondents do not show a difference. The K-12 graduates' compositional errors do not differ significantly from that in the Alternative Learning System (ALS) passers or the old basic education curriculum graduates. It is in delivery that students vary. This finding implies that college students' compositional skills still need strengthening. Instructors are encouraged to provide comprehensive activities and writing exercises to both genders, regardless of their curriculum. It is recommended that university language instructors identify specific interventions to help students struggling with writing. Therefore, providing enough written opportunities and practices is vital to make college students enhance their compositional skills.

Oestrosis koyun ve keçilerin burun ve sinus boşluğunda Oestrus ovis sineğinin larvalarının neden olduğu paraziter bir hastalıktır. Dünyanın sıcak ve kuru bölgelerinde, özellikle Avrupa, Afrika ve Akdeniz'de oldukça yaygındır (1-6). Küçükbaş hayvanların otlatılması sırasında sineklerin neden olduğu ra-hatsızlık ve larva gelişimi sırasındaki etkileri hayvancılık üretimi üzerinde ciddi sonuçlar doğurabilmektedir. Ergin sineklerin burun etrafına bıraktıkları birinci dönem larvalar hızlı bir şekilde burun boşluğuna, burun septumlarına, turbinate ve etmoid kemiklere yerleşerek mukoza ve mukoza salgıları ile beslenerek büyür ve frontal sinuslere doğru ilerleyerek gelişimlerini tamamlarlar. Hayvanlarda enfekte bölgeye ve larva Dicle Üniversitesi Veteriner Fakültesi Dergisi Araştırma Makalesi/Research Article

The gene that codes for the putative dihydroorotase in the hyperthermophilic archaeon Methanococcus jannaschii was subcloned in pET-21a and expressed in Escherichia coli. A purification protocol was devised. The purity of the protein was evaluated by SDS-PAGE and the protein was confirmed by sequencing using LC-MS. The calculated molecular mass is 48104 Da. SEC-LS suggested that the protein is a monomer in solution. ICP-MS showed that there are two Zn ions per monomer. Kinetic analysis of the recombinant protein gave hyperbolic kinetics with Vmax = 12.2 µmol/min/mg and Km = 0.14 mM at 25 °C. Furthermore the activity of the protein increased with temperature consistent with the hyperthermophilic nature of the organism. A homology model was constructed using the mesophilic Bacillus anthracis protein as the template. Residues known to be critical for Zn and substrate binding were conserved. The activity of the enzyme at 85 and 90 °C was found to be relatively constant over 160 min and ...

A series of N,N-disubstituted piperazines were synthesized containing the structural elements of both methylenedioxybenzylpiperazine (MDBP) and trifluoromethylphenylpiperazine (TFMPP) in a single molecule. These six potential designer drug molecules having a regioisomeric relationship were compared in gas chromatography-mass spectrometry (GC-MS), gas chromatography-infrared spectroscopy and serotonin receptor affinity studies. These compounds were separated by capillary gas chromatography on an Rxi Ò -17Sil MS stationary phase film and the elution order appears to be determined by the position of aromatic ring substitution. The majority of electron ionization mass spectral fragment ions occur via processes initiated by one of the two nitrogen atoms of the piperazine ring. The major electron ionization mass spectrometry (EI-MS) fragment ions observed in all six of these regioisomeric substances occur at m/z = 364, 229, 163 and 135. The relative intensity of the various fragment ions is also equivalent in each of the six EI-MS spectra. The vapour phase infrared spectra provide a number of absorption bands to differentiate among the six individual compounds on this regioisomeric set. Thus, the mass spectra place these compounds into a single group and the vapour phase infrared spectra differentiate among the six regioisomeric possibilities. All of the TFMPP-MDBP regioisomers displayed significant binding to 5-HT 2B receptors and in contrast to 3-TFMPP, most of these TFMPP-MDBP isomers did not show significant binding at 5-HT 1 receptor subtypes. Only the 3-TFMPP-3,4-MDBP (Compound 5) isomer displayed affinity comparable to 3-TFMPP at 5-HT 1A receptors (K i = 188 nmol/L).

Glioblastoma is the most frequent and malignant brain tumor. Treatment includes chemotherapy with temozolomide concomitant with surgical resection and/or irradiation. However, a number of cases are resistant to temozolomide, as well as the human glioblastoma cell line U138-MG. We investigated doxazosin's (an antihypertensive drug) activity against glioblastoma cells (C6 and U138-MG) and its neurotoxicity on primary astrocytes and organoptypic hippocampal cultures. For this study, the following methods were used: citotoxicity assays, flow cytometry, western-blotting and confocal microscopy. We showed that doxazosin induces cell death on C6 and U138-MG cells. We observed that doxazosin's effects on the PI3K/Akt pathway were similar as LY294002 (PI3K specific inhibitor). In glioblastoma cells treated with doxasozin, Akt levels were greatly reduced. Upon examination of activities of proteins downstream of Akt we observed upregulation of GSK-3β and p53. This led to cell proliferation inhibition, cell death induction via caspase-3 activation and cell cycle arrest at G0/G1 phase in glioblastoma cells. We used in this study Lapatinib, a tyrosine kinase inhibitor, as a comparison with doxazosin because they present similar chemical structure. We also tested the neurocitotoxicity of doxazosin in primary astrocytes and organotypic cultures and observed that doxazosin induced cell death on a small percentage of non-tumor cells. Aggressiveness of glioblastoma tumors and dismal prognosis require development of new treatment agents. This includes less toxic drugs, more selective towards tumor cells, causing less damage to the patient. Therefore, our results confirm the potential of doxazosin as an attractive therapeutic antiglioma agent.

A coupled analysis of the reaction kinetics and microstructural changes of Fe 2 O 3 /Al 2 O 3 oxygen carriers during redox reaction cycles for chemical looping systems was conducted. The microstructural changes in the oxygen carrier particles were investigated using an image analysis method with cross-sectional backscattered electron images, and microstructural information such as the particle size, porosity, and two-phase boundary between the iron oxide and pores was obtained. The microstructural changes and the degradation kinetics during redox cycles were investigated under various operating conditions (reaction temperatures, reduction times, oxygen partial pressures during the oxidation process, and weight ratios of the oxygen carriers). The degradation coefficient and the reaction enthalpy of the particles in the oxidation process are linearly related, implying that increasing the local temperature of the oxygen carriers causes the coarsening of iron oxide particles via sintering and microstructural changes. Our analysis contributes to the design of highly stable oxygen carrier particles and the improvement of the operating conditions for chemical looping systems.

A coupled analysis of the reaction kinetics and microstructural changes of Fe 2 O 3 /Al 2 O 3 oxygen carriers during redox reaction cycles for chemical looping systems was conducted. The microstructural changes in the oxygen carrier particles were investigated using an image analysis method with cross-sectional backscattered electron images, and microstructural information such as the particle size, porosity, and two-phase boundary between the iron oxide and pores was obtained. The microstructural changes and the degradation kinetics during redox cycles were investigated under various operating conditions (reaction temperatures, reduction times, oxygen partial pressures during the oxidation process, and weight ratios of the oxygen carriers). The degradation coefficient and the reaction enthalpy of the particles in the oxidation process are linearly related, implying that increasing the local temperature of the oxygen carriers causes the coarsening of iron oxide particles via sintering and microstructural changes. Our analysis contributes to the design of highly stable oxygen carrier particles and the improvement of the operating conditions for chemical looping systems.

One of the traditional ways of preparation of yogurt starter in Bulgaria is placing a branch of a particular plant species into boiled sheep's milk maintained at about 45 1C, which is further incubated until a dense coagulum is obtained. To investigate the possible origin of the yogurt starter bacteria, Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) and Streptococcus thermophilus (S. thermophilus), the traditional way of yogurt-starter preparation was followed. Hundreds of plant samples were collected from four regions in Bulgaria and incubated in sterile skim milk. The two target bacteria at low frequencies from the plant samples collected were successfully isolated. Phenotypic and genotypic characteristics of these bacterial isolates revealed that they were identified as L. bulgaricus and S. thermophilus. Twenty isolates of L. bulgaricus and S. thermophilus, respectively, were selected from the isolated strains and further characterized with regard to their performance in yogurt production. Organoleptic and physical properties of yogurt prepared using the isolated strains from plants were not significantly different from those prepared using commercial yogurt-starter strains. It was therefore suggested that L. bulgaricus and S. thermophilus strains widely used for commercial yogurt production could have originated from plants in Bulgaria. To our knowledge, this is the first report on the isolation and characterization of L. bulgaricus and S. thermophilus strains from plants.

␤-alanine (Ala) betaine, an osmoprotectant suitable under saline and hypoxic environments, is found in most members of the halophytic plant family Plumbaginaceae. In Limonium latifolium (Plumbaginaceae), it is synthesized via methylation of ␤-Ala by the action of a trifunctional S-adenosyl l-methionine (Ado-Met): ␤-Ala N-methyltransferase (NMTase). Peptide sequences from purified ␤-Ala NMTase were used to design primers for reverse transcriptase-PCR, and several cDNA clones were isolated. The 5Ј end of the cDNA was cloned using a 5Ј-rapid amplification of cDNA ends protocol. A 500-bp cDNA was used as a probe to screen a -gt10 L. latifolium leaf cDNA library. Partial cDNA clones represented two groups, NMTase A and NMTase B, differing only in their 3Ј-untranslated regions. The full-length NMTase A cDNA was 1,414 bp and included a 1128-bp open reading frame and a 119-bp 5Ј-untranslated region. The deduced amino acid sequence of 375 residues had motifs known to be involved in the binding of Ado-Met. The NMTase mRNA was expressed in L. latifolium leaves but was absent in Limonium sinuatum, a member of the genus that lacks the synthetic pathway for ␤-Ala betaine. NMTase mRNA expression was high in young and mature leaves and was enhanced by light. NMTase cDNA was expressed in yeast (Saccharomyces cerevisiae) under the control of a galactose-inducible promoter. Protein extracts of galactose-induced recombinant yeast had Ado-Met-specific NMTase activities that were highly specific to ␤-Ala, N-methyl ␤-Ala, and N,N-dimethyl ␤-Ala as methyl acceptors. NMTase activities were not detectable in comparable protein extracts of yeast, transformed with vector control. The NMTase protein sequence shared homology with plant caffeic acid O-methyltransferases and related enzymes. Phylogenetic analyses suggested that ␤-Ala NMTase represents a novel family of N-methyltransferases that are evolutionarily related to O-methyltransferases.

Traditional materials from new sourcesconflicts in analytical methods for calcium carbonate. Calcium carbonate, (E170) is a common food and pharmaceutical additive/ingredient. In addition to a source of calcium, the carbonate has uses including as a colour, acidity regulator and bulking agent. Globally, a range of regulatory agencies and pharmacopoeia control the analyses and specification of additives in food, supplements, pharmaceutical substances and excipients. Accordingly, a range of specifications and analyses exist for calcium carbonate depending on the application and market of the product. In this contribution, we analyse calcium carbonates from geological, synthetic and biogenic sources, focussing on acid insoluble impurities, a test required by current monographs. Analysis of calcium carbonate from different origins may require modification of existing tests to comply with regulatory bodies, due to the variation of impurities specific to the source of the material. We suggest an analytical approach involving centrifugation that improves analytical efficiency (up to 85% time reduction), especially for calcium carbonate of biological origin.

New methods for peptide modification are in high demand in drug discovery, chemical biology and materials chemistry; methods that modify natural peptides are particularly attractive. A Pd-catalyzed, C-H functionalization protocol for the olefination of phenylalanine residues in peptides is reported, which is compatible with common amino acid protecting groups, and the scope of the styrene reaction partner is broad. Bidentate coordination of the peptide to the catalyst appears crucial for the success of the reaction.

Escherichia coli is the most widely used protein production host in academia and a major host for industrial protein production. However, recombinant production of eukaryotic proteins in prokaryotes has challenges. One of these is post-translational modifications, including native disulfide bond formation. Proteins containing disulfide bonds have traditionally been made by targeting to the periplasm or by in vitro refolding of proteins made as inclusion bodies. More recently, systems for the production of disulfide-containing proteins in the cytoplasm have been introduced. However, it is unclear if these systems have the capacity for the production of disulfide-rich eukaryotic proteins. To address this question, we tested the capacity of one such system to produce domain constructs, containing up to 44 disulfide bonds, of the mammalian extracellular matrix proteins mucin 2, alpha tectorin, and perlecan. All were successfully produced with purified yields up to 6.5 mg/L. The proteins were further analyzed using a variety of biophysical techniques including circular dichroism spectrometry, thermal stability assay, and mass spectrometry. These analyses indicated that the purified proteins are most likely correctly folded to their native state. This greatly extends the use of E. coli for the production of eukaryotic proteins for structural and functional studies.

Escherichia coli is the most widely used protein production host in academia and a major host for industrial protein production. However, recombinant production of eukaryotic proteins in prokaryotes has challenges. One of these is post-translational modifications, including native disulfide bond formation. Proteins containing disulfide bonds have traditionally been made by targeting to the periplasm or by in vitro refolding of proteins made as inclusion bodies. More recently, systems for the production of disulfide-containing proteins in the cytoplasm have been introduced. However, it is unclear if these systems have the capacity for the production of disulfide-rich eukaryotic proteins. To address this question, we tested the capacity of one such system to produce domain constructs, containing up to 44 disulfide bonds, of the mammalian extracellular matrix proteins mucin 2, alpha tectorin, and perlecan. All were successfully produced with purified yields up to 6.5 mg/L. The proteins...

RNA S′‐terminal phosphate cyclase has been purified about 6000‐fold to near homogeneity from HeLa cells. The purified protein is a single polypeptide with an Mr of 38000‐40000 and a Stokes radius of 2.66 nm. The cyclase shows a pH optimum of 8.0‐9.0. In the presence of Mg 2+ and ATP this enzyme catalyzes the conversion of a 3′‐phosphate group into the cyclic 2′,3′‐phosphodiester at the 3′ end of RNA, through formation of a covalent cyclase‐AMP intermediate. GTP, CTP and UTP (but not dATP or ADP) can also function as cofactors in the cyclization reaction, although less efficiently (apparent Km values for ATP and GTP are 6 μM and 200 μM, respectively). Consistent with this, the enzyme can be covalently labelled with the four [α‐32P]NTPs.

We have performed functional genomics of salt stress by overexpression of gene libraries in yeast and selection for salt tolerance. Thirty halotolerance genes were isolated from yeast, Arabidopsis, and sugar beet. The results indicate that Na þ transport (uptake, efflux, and compartmentation), sulfate activation, RNA processing, and protein synthesis are crucial for salt tolerance.

Protein kinases dedicated to the phosphorylation of SR proteins have been implicated in the processing and nuclear export of mRNAs. Here we demonstrate in Saccharomyces cerevisiae their participation in cation homeostasis. A null mutant of the single yeast SR protein kinase Sky1p is viable but exhibits increased tolerance to diverse toxic cations such as Na + , Li + , spermine, tetramethylammonium, hygromycin B and Mn 2 + . This pleiotropic phenotype correlates with reduced accumulation of cations, suggesting a decrease in membrane electrical potential. Genetic analysis and Rb + uptake measurements indicate that Sky1p modulates Trk1,2, the high-affinity K + uptake system of yeast and a major determinant of membrane potential.

Las especies de Anaplasma de la familia Anaplasmataceae (orden Rickettsiales) son bacterias intracelulares, el vector transmisor son garrapatas, que causan enfermedad de anaplasmosis en animales domésticos como rumiantes, perros, animales salvajes y humanos a nivel mundial. Anaplasmosis es una enfermedad hemoparasitaria, originada por bacterias del género Anaplasma marginale, sus signos clínicos son: fiebre, anemia e ictericia. Todos los grupos de edad son susceptibles, pero la prevalencia aumenta con la edad. En el presente documento se describe un caso clínico de Anaplasmosis bovina presentado en un bovino de propietario externo en el que se realizó el diagnostico en el laboratorio de

About 60% of the bean crop is cultivated under the risk of either intermittent or terminal drought (White and Sing, 1991). The effects of drought on common bean are dependent on the intensity, type and duration of the stress. In Africa as much as 300,000 Mg of beans are lost to drought annually (Wortmann et al., 1998). Highland Mexico, Central America, northeast Brazil, and much of eastern Africa are bean producing areas where drought is endemic. Development of drought adapted bean varieties is an important strategy to minimize crop failure and improve food security in bean growing regions (Rao, 2001). Previous research indicated that the superior performance of common bean genotypes under drought was associated with their ability to mobilize photosynthates to developing grain and to utilize the acquired N and P more efficiently for grain production. The main objective of the present study is to evaluate drought adaptation of elite lines from the on-going breeding program (Beebe et al., 2008) to quantify phenotypic differences in drought resistance under field conditions and to define the physiological basis for improved drought adaptation.

Previous studies have shown that polyethylene glycol (PEG)-induced osmotic stress (OS) reduces cell-wall (CW) porosity and limits aluminium (Al) uptake by root tips of common bean (Phaseolus vulgaris L.). A subsequent transcriptomic study suggested that genes related to CW processes are involved in adjustment to OS. In this study, a proteomic and phosphoproteomic approach was applied to identify OS-induced protein regulation to further improve our understanding of how OS affects Al accumulation. Analysis of total soluble proteins in root tips indicated that, in total, 22 proteins were differentially regulated by OS; these proteins were functionally categorized. Seventy-seven percent of the total expressed proteins were involved in metabolic pathways, particularly of carbohydrate and amino acid metabolism. An analysis of the apoplastic proteome revealed that OS reduced the level of five proteins and increased that of seven proteins. Investigation of the total soluble phosphoproteome suggested that dehydrin responded to OS with an enhanced phosphorylation state without a change in abundance. A cellular immunolocalization analysis indicated that dehydrin was localized mainly in the CW. This suggests that dehydrin may play a major protective role in the OS-induced physical breakdown of the CW structure and thus maintenance of the reversibility of CW extensibility during recovery from OS. The proteomic and phosphoproteomic analyses provided novel insights into the complex mechanisms of OS-induced reduction of Al accumulation in the root tips of common bean and highlight a key role for modification of CW structure.

Common bean (Phaseolus vulgaris L.) is the most important food legume in tropical Latin America and East and southern Africa. Beans originated in the mid-altitude neotropics with moderate soil fertility conditions. Typically, they are not well adapted to extreme climatic and edaphic environments. Climate change will alter distribution and intensity of biotic constraints to bean production, and more intense droughts will adversely affect important production regions in Mexico, Central America, the Caribbean, and southern Africa. In the tropics the crop is cultivated largely by resource-poor farmers, often on soils that are deficient in nitrogen and phosphorus. Both climatic and edaphic constraints cause severe yield losses. They are widespread, often intense, and occur every year in the case of heat and soil problems. Developing the right root system to cope with root rots, drought, and soil problems in each production environment will be a major research challenge. Genetic improvement for resistance to major biotic and abiotic constraints will have significant and wide impact. Fertilizers that improve plant vigor, root growth, and access to soil moisture, or irrigation to counter drought, are seldom viable options for small-scale farmers. While programs to subsidize such inputs merit consideration, crop improvement through plant breeding will probably be the cornerstone of adapting beans to climate-smart production systems in the tropics. The secondary and tertiary gene pools of common bean cover a range of environments from cool moist highlands to hot semi-arid regions, and will be important resources for the genetic improvement of common bean as it must increasingly confront extremes of heat, drought, and excess moisture. Contents 2 Background information and system description 3 Major constraints for target production system 6 Key eco-efficiency interventions throughout the value chain 10 Risk and resilience issues 10 Adaptation to and mitigation of the effects of climate change 13 Quantifying eco-efficiency and developing indicators 14 Opportunities to enhance impact and scale-out from initial studies and interventions 14 Perspectives: key lessons and opportunities for research, development, and policy 15 Acknowledgements 15 References

New evidence is provided regarding the direct effect of light on stomatal opening in the epidermis of the pea (Pisum sativwn L. var Little Marvel) leaf. Lght modulates the activity of a number of key enzymes involved in stomatal metabolism. When Isolated epidermal strips are illuminated, phosphoenolpyruvate carboxylase, NADP-malate dehydrogenase, and NADP-isocltrate debydrogenase are activated; and aspartate aminotrans- ferase is inactivated. Sulfhydryl compounds, dithiothreitol and glutathione, enhance stomatal opening in epidermal strips both in lght or darkness while the sulHhydryl reagent N-ethylmaleinide hibits, inUcating the possible involvement of sulihydryl groups in stomatal movements. Further, light treatment increases measureable thiol levels in the epidermis about 3-fold. These results suggest that lght modulation of enzymes in the epidermis may play a significant role in the mechanism of stomatal movement. Stomatal movements are caused by changes in guard cell turgor arising from the movement of K+ and H+ (11, 13) with electroneutrality being maintained by movement of C1-or internal production of malate (1, 16). The occurrence of wider stomatal opening with increasing light intensity and of smaller apertures in the dark than in the light has been known for some time (4). Sharkey and Raschke (19) measured the magnitude of the direct and indirect effects of light on stomatal movement. The stomatal response to light was determined to be a direct response to light and, to a small extent only, a response to changes in intercellular CO2 concentration. The presence of both photosystems in guard cell chloroplasts was shown by the elegant experiments of Outlaw (13). Because the reductive step enzyme of the photosynthetic carbon reduction cycle (NADP-linked glyceraldehyde-3-P dehydrogenase) is absent in guard cells, Outlaw (13) suggested that noncyclic photosynthetic electron flow is an environmental sensor which causes stomata to remain open in light. It was further pointed out that one of the important physiological changes associated with H20 oxidation by photosynthetic electron transport might be the modulation of enzyme activity in the guard cells. Light modulation of the activity of the enzymes of photosyn- thetic carbon metabolism has been shown to occur in C3, C4, and CAM plants (2). The enzymic equipment for malic acid carboxy- lation and decarboxylation as well as its compartmentation in guard cells shows many similarities with those of C4 and CAM 'Supported by Department of Energy Contract EP 78-S-02 1961.

 Traditional crop of the deserts and semi-arid regions of Mexico and southwestern USA .It is a minor crop compared to common bean and is used only for subsistance.  Highly tolerant to drought and high temperature. Has a high potential of adaptation to the climate change.  The genetic base of cultivated tepary accessions is narrow. A reason for this reduced genetic variability might be the historic regression of tepary after the introduction of new wattering technonologies in Mesoamerica after 1492 (Nabhan & Felger 1978, Debouck 1992).  The genetic extinction in tepary led to the loss of variation in seed color.  Induced mutation is a powerful tool for tepary crop improvement and to develop new mutant varieties showing a greater diversity. Traits that are of interest for tepary are: uniform red seed color and erect growth habit. The objectives of the present study were:  To generate genetic variability among tepary lines.  To evaluate the tepary bean M 6 mutated lines under stress of drought and/or high temperature and identify heat and drought tolerant mutant lines.

Common bean (Phaseolus vulgaris L.) is the most important grain legume for human consumption and drought stress affects over 60% of dry bean production worldwide. Field studies were conducted over two seasons at Centro Internacional de Agricultura Tropical (CIAT), Palmira, Colombia to (i) evaluate phenotypic differences in drought resistance; and (ii) identify adaptive traits that can be used in on-going breeding programmes of common bean for developing drought resistant genotypes. A total of 36 genotypes, including elite inbred and interspecific lines and landraces of common bean and tepary bean were evaluated under field conditions with two levels of water supply (irrigated and rainfed). Results showed that two accessions of tepary bean, P. acutifolius (G 40159 and G 40068) and two elite lines (RAB 650, SEA 23) of common bean were outstanding in their adaptation to terminal drought stress. The superior performance of these genotypes under drought stress was associated with their ability to mobilise photosynthates from leaves and stems to developing grain. Tepary bean was superior to common bean in combinig several desirable traits that contribute to greater level of adaptation to terminal drought stress. Canopy biomass, pod partitioning index, stem biomass reduction and pod harvest index could serve as useful traits to improve the efficiency of breeding programmes to select superior genotypes of common bean under terminal drought stress.

legume, with an annual production value of over US$10 billion. It is produced mainly on small-scale farms (80% of dry bean production) in developing countries in Latin America and Africa. About 40% of the beangrowing area is affected by aluminum (Al) toxicity, resulting in decrease of grain yield from 30% to 60%. It needs significant improvement in Al resistance to reduce the dependence of small farmers on lime and fertilizer inputs. Genetic variation exists for acid soil adaptation (Rao et al., 2004) and Al resistance (Rangel et al., 2005) among common bean genotypes. The most frequently measured effect of excess Al is inhibition of root elongation (Rangel et al., 2005). Nutrient solution culture allows evaluation of a large number of genotypes quickly and could be very useful for identification of (i) parental genotypes with contrasting root architecture for bean breeding, (ii) contrasting genotypes for physiological analysis, (iii) QTLs related to Al resistance, and (iv) candidat...

Two common bean (Phaseolus vulgaris L.) genotypes differing in aluminum (Al) resistance, Quimbaya (Al-resistant) and VAX-1 (Al-sensitive) were grown in hydroponics for up to 25 h with or without Al, and several parameters related to the exudation of organic acids anions from the root apex were investigated. Al treatment enhanced the exudation of citrate from the root tips of both genotypes. However, its dynamic offers the most consistent relationship between Al-induced inhibition of root elongation and Al accumulation in and exclusion from the root apices. Initially, in both genotypes the short-term (4 h) Al-injury period was characterized by the absence of citrate efflux independent of the citrate content of the root apices, and reduction of cytosolic turnover of citrate conferred by a reduced Nicotinamide adenine dinucleotide phosphate-isocitrate dehydrogenase (EC 1.1.1.42) activity. Transient recovery from initial Al stress (4-12 h) was found to be dependent mainly on the capacity to utilize internal citrate pools (Al-resistant genotype Quimbaya) or enhanced citrate synthesis [increased activities of NAD-malate dehydrogenase (EC 1.1.1.37) and ATP-phosphofructokinase (EC 2.7.1.11) in Al-sensitive VAX-1]. Sustained recovery from Al stress through citrate exudation in genotype Quimbaya after 24 h Al treatment relied on restoring the internal citrate pool and the constitutive high activity of citrate synthase (CS) (EC 4.1.3.7) fuelled by high phosphoenolpyruvate carboxylase (EC 4.1.1.31) activity. In the Alsensitive genotype VAX-1 the citrate exudation and thus Al exclusion and root elongation could not be maintained coinciding with an exhaustion of the internal citrate pool and decreased CS activity.

Ro 28-2653 (RO) is a synthetic inhibitor of matrix metalloproteinases (MMPs), which is potentially effective against bronchial remodeling. Given that this molecule has very poor aqueous solubility, different cyclodextrins (CDs) have been tested to increase its solubility. The aim of this study was to prepare and to characterize inclusion complexes between RO and CDs, in order to develop nebulizable solutions. The complex formation was investigated by phase solubility studies. (1)H-NMR spectroscopy and molecular modeling studies were carried out to elucidate the structure of the inclusion complex between RO and dimethyl-beta-CD (DIMEB). Nebulizable solutions of RO were developed with CDs and a stability study was performed over 9 months. The phase solubility studies showed that beta-CD and its derivatives form a 1:2 complex with RO, whereas gamma-CD includes RO with a 1:1 stoichiometry and a weak stability constant. T-ROESY spectra showed that DIMEB is able to complex two RO substitu...

This article draws on the recent transnational protests against racist police brutality to advance an understanding of robust intersectional solidarity which aims to improve over Mara Marin's Iris Young-inspired 'structural solidarity' view. The latter view helpfully grounds robust intersectional solidarity in the racial structure, but it neglects the fact that racial domination exerts such a segregative influence on social groups that whites and middle-class blacks tend not to frequent the social milieux that would help them develop the required sense of solidarity with workingclass blacks. To address this problem, the article hypothesises that the conditions for robust intersectional solidarity against racism are not inherent in the racial structure but created by social movements, as exemplified by Black Lives Matter: to the extent that white and middle-class black participants in the George Floyd protests experienced something like the racist police brutality they were denouncing on behalf of the black working class, these protests functioned as non-segregated milieux that could ground the robust solidarity of the former with the latter at the national and transnational levels.

Monitoring tests form an increasing proportion of the workload in clinical biochemistry and biochemists can help by providing clinicians with information about the variability and precision of tests, the time frame for pharmacodynamic stabilisation after a treatment change, and the frequency of testing. This paper outlines the phases of monitoring, and how to decide if monitoring is beneficial, which test to use for monitoring, when a change in the test result indicates a need for the change in treatment and the length of testing intervals. We conclude with some recommendations for biochemists for future areas of research and advice that can be given to clinicians.

P-selectin is a 140 kDa membrane glycoprotein found in secretory granules of platelets and endothelial cells where it is rapidly translocated to the plasma membrane upon cell activation. It then functions as a receptor for various types of leucocytes. Metabolic labelling of resting platelets with 32Pi showed that P-selectin is primarily phosphorylated on serine residues, although some tyrosine phosphorylation was observed as well. However, tyrosine phosphorylation of P-selectin was greatly stimulated by treatment with the permeating phosphatase inhibitor, pervanadate. When P-selectin immunoprecipitates were incubated with [gamma-32P]ATP (in vitro kinase assay), a fraction of P-selectin was phosphorylated on its tyrosine residues by a co-precipitated kinase. P-selectin phosphorylated in vitro co-migrated with 140 kDa surface-labelled 125I-P-selectin during SDS/PAGE under reducing conditions. Under non-reducing conditions, however, phosphorylated P-selectin was disulphide-linked to un...

Over evolutionary time, pathogen challenge shapes the immune phenotype of the host to better respond to an incipient threat. The extent and direction of this selection pressure depend on the local pathogen composition, which is in turn determined by biotic and abiotic features of the environment. However, little is known about adaptation to local pathogen threats in wild animals. The Gentoo penguin (Pygoscelis papua) is a species complex that lends itself to the study of immune adaptation because of its circumpolar distribution over a large latitudinal range, with little or no admixture between different clades. In this study, we examine the diversity in a key family of innate immune genes—the Toll-like receptors (TLRs)—across the range of the Gentoo penguin. The three TLRs that we investigated present varying levels of diversity, with TLR4 and TLR5 greatly exceeding the diversity of TLR7. We present evidence of positive selection in TLR4 and TLR5, which points to pathogen-driven ad...

Several neurodegenerative diseases, like Alzheimer's (AD), are characterized by amyloid fibrillar deposition of misfolded proteins, and this feature can be exploited for both diagnosis and therapy design. In this paper, structural modifications of curcumin scaffold were examined in order to improve its bioavailability and stability in physiological conditions, as well as its ability to interfere with β-amyloid fibrils and aggregates. The acid-base behaviour of curcumin derivatives, their pharmacokinetic stability in physiological conditions, and in vitro ability to interfere with Aβ fibrils at different incubation time were investigated. The mechanisms governing these phenomena have been studied at atomic level by means of molecular docking and dynamic simulations. Finally, biological activity of selected curcuminoids has been investigated in vitro to evaluate their safety and efficiency in oxidative stress protection on hippocampal HT-22 mouse cells. Two aromatic rings, π-conju...

Renin is the initial rate limiting step in the renin angiotensinogen system (RAS). To combat hypertension, various stages of the RAS can be positively affected. The aim of this study was to isolate and characterize renin inhibitory peptides from the red seaweed P. palmata for use in functional foods. Palmaria palmata protein was extracted and hydrolyzed with the food grade enzyme Papain to generate renin inhibitory peptides. Following proteolytic hydrolysis of P. palmata protein, reverse phasehigh performance liquid chromatography (RP-HPLC) was employed to enrich for peptides with renin inhibitory activities. Fraction 25 (Fr-25) inhibited renin activities by 58.97% (±1.26) at a concentration of 1 mg/mL. This fraction was further characterized using nano-electrospray ionization quadropole/time-of-flight mass spectrometry (ESI-Q/TOF MS). A number of novel peptide sequences were elucidated, and the parent protein from which they were derived was determined using MS in tandem with protein database searches. All sequences were confirmed using de novo sequencing. The renin inhibitory peptide Ile-Arg-Leu-Ile-Ile-Val-Leu-Met-Pro-Ile-Leu-Met-Ala (IRLIIVLMPILMA) was chemically synthesized and its bioactivity confirmed using the renin inhibitory assay. Other stages of the RAS have recently been inhibited by bioactive peptides sourced from macroalgae, but this is the first study to isolate and characterize renin inhibitory peptides from the macroalgae.

Four low-molecular-mass polypeptides were isolated and purified from chromatophore membranes of Rhodopseudomonas spliaeroides blue-green mutant R-26.1 by a combination of gel filtration and ion-exchange chromatography in organic solvents. On dodecyl sulfate polyacrylamide gels, the purified polypeptides comigrate with bands LH-1, LH-2 and LH-3 known to be related to the antennapigment-protein complexes. The complete primary structures were elucidated by automated Edman degradation of the intact polypeptides and of overlapping C-terminal fragments obtained after chemical cleavage at tryptophan and methionine residues. The C-termini were verified by hydrazinolysis and, in one case where an overlapping C-terminal fragment could not be obtained, by digestion with carboxypeptidase A. The four polypeptides show a tripartite structure: i.e. a polar N-terminal region is separated from a polar C-terminal region by a segment of about 21 predominantly hydrophobic amino-acid residues. All hydrophobic segments contain a characteristic conservative histidine residue. The C-terminal region is reduced to only a few amino acids in the two polypeptides which together form band LH-3, i.e. LH-3A and LH-3B. Their extended Nterminal region is rich in charged residues and contains an additional conserved histidine residue close to the beginning of the hydrophobic segment. These properties place LH-3A and LH-3 B into subgroup ( -polypeptides: B 870-0 and B 850-0, respectively). LH-1 and LH-2 appear to form another subgroup (a-polypeptides: Β 870-α and Β 850-α, respectively) as suggested during a search for conservative elements within their sequences (structural basis for classification). N-Terminal analyses carried out with intact antenna-pigment-protein complexes revealed the following: (i) LH-1 and LH-3A are associated with the Β 870 complex in Rp. sphaeroides 2 4.1 (wild type), (ii) the same polypeptides are almost exclusively present in chromatophore membranes of Rp. sphaeroides R-26, a blue-green mutant which absorbs at 870 nm, (iii) LH-2 and LH-3 Β are the constituent polypeptides of the Β 800-850 complex of Rp. sphaeroides 2.4.1 and of the spectrally altered Β 850 complex isolated from the blue-green mutant R-26.1 which absorbs at 860 nm. This mutant contains LH-2 and LH-3B along with LH-1 and LH-3A h'nzyme: Carboxypeptidase A, peptidyl-L-amino acid hydrolase (EC 3.4.17.1). Abbreviations: C/M/NH 4 OAc, chloroform/methanol =1:1 (v/v) containing lOOmM NH 4 OAc; polybrene, 1,5-dimethyl-l ,5-diazaundecamethylen-polymethobromide; Quadrol, yV r ,^V,A^',A^'-tetrakis(2-hydroxypropyl)-ethylenediamine.

Para-substituted iodobenzenes were reacted with tert-butyl isocyanide and piperidine as nucleophiles in the presence of palladium-diphosphine catalysts. Both single and double insertion of the isocyanide was observed and the corresponding amidines and ketimine-amidines were obtained in yields of practical interest. With the increase of the tert-butyl isocyanide/iodobenzene ratio, 100% chemoselectivity toward the ketimine-amidine was achieved. The formation of the products was rationalized on the basis of a catalytic cycle analogous to that of the aminocarbonylation reactions. Clear connection was found between the activity and the electronic structure of the proposed catalyst Pd(diphosphine) by computational studies, as the more negative partial charge on palladium resulted in higher conversion. Among five isocyanide substrates, only tert-butyl isocyanide was proved to be active.

Recent evidence has exhibited dietary influence on the manifestation of depressive-like behaviour induced by stressor tasks. The present study examined the effects of Tualang honey supplement administered with the goal of preventing or attenuating the occurrence of depressive-like behaviour in male rats subjected to noise stress. Forty-eight adult male rats were randomly divided into the following groups: i) nonstressed with placebo, ii) nonstressed with honey, iii) stressed with placebo, and iv) stressed with honey. Tualang honey (200 mg/kg body weight) was administered for 28 days. Stressed rats were subjected to loud noise 100 dB(A) 4 hours daily for 14 days. Forced swimming test was performed to evaluate depressive-like behaviour. Stressed control rats displayed significant increase in depressive-like behaviour, serum adrenocorticotropic hormone (ACTH), corticosterone, and brain oxidative stress markers levels, with significant decrease in antioxidant enzymes activities and tota...

Adverse health effects caused by heavy metal toxicity, particularly lead, commonly manifest in children due to their higher absorption rate and frequent exposure from play areas such as school grounds. The aim of this study is to: (1) determine lead levels in soil and plant samples and compare to US EPA acceptable limits; and (2) assess health risk by determining if an association exists between the occurrence of physical and neurological symptoms of lead poisoning among the pre-school children in Manila (exposed group) and pre-school children in Bataan (unexposed group). Using flame absorption spectroscopy, it was found that lead levels in plant species and soil samples ranged from 0.11-0.16 ppm and 1.12-2.59, respectively. These were still within the limits set by US EPA at 300 ppm (plants) and 400 ppm (soil). However, if accidentally ingested, the amount absorbed would exceed serum safe level of 10 mcg/dl, leading to possible toxicity. On the other hand, the cross-sectional surve...

Automated Writing Evaluation (AWE) tools have not only confidently entered the scene of digital writing technologies but also secured a prominent space in teaching and learning practices due to their formative automated feedback on various traits of the writing construct. The nature and types of AWE feedback vary depending on the history and origins of the tools. Having evolved through multiple generations, they can be broadly categorized as assessment-driven and genre-based. This chapter elaborates on both of these ramifications of AWE, describing their purposes, functional specifications, and two exemplary tools. AWE research has been increasingly adopting the validity argument framework, which allows to consolidate multifarious evidence into a progression of empirically supported inferences about AWE uses. To that end, AWE effectiveness has been investigated in terms of: how well the tools represent the target writing domains; how accurate, consistent, and appropriate the feedbac...

Three water-soluble Ru(II) chiral heteroleptic coordination compounds [Ru(en)(pdto)]Cl2 (1), [Ru(gly)(pdto)]Cl (2), and [Ru(acac)(pdto)]Cl (3), where pdto = 2,2'-[1,2-ethanediylbis-(sulfanediyl-2,1-ethanediyl)]dipyridine, en = ethylendiamine, gly = glycinate, and acac = acetylacetonate, have been synthezised and fully characterized. The crystal structures of compounds 1-3 are described. The IC50 values for compounds 1-3 are within nanomolar range (14, 12, and 6 nM, respectively). The cytotoxicity for human peripheral blood lymphocytes is extremely low (>100 μM). Selectivity indexes for Ru(II) compounds are in the range 700-1300. Trophozoites exposed to Ru(II) compounds die through an apoptotic pathway triggered by ROS production. The orally administration to infected mice induces a total elimination of the parasite charge in mice faeces 1-2-fold faster than metronidazole. Besides, all compounds inhibit the trophozoite proliferation in amoebic liver abscess induced in hamster....

ABSTRACTMitochondria are required for energy production and even give brown adipose tissue (BAT) its characteristic color due to their high iron content and abundance. The physiological function and bioenergetic capacity of mitochondria are connected to the structure, folding, and organization of its inner-membrane cristae. During the aging process, mitochondrial dysfunction is observed, and the regulatory balance of mitochondrial dynamics is often disrupted, leading to increased mitochondrial fragmentation in aging cells. Therefore, we hypothesized that significant morphological changes in BAT mitochondria and cristae would be present with aging. We developed a quantitative three-dimensional (3D) electron microscopy approach to map cristae network organization in mouse BAT to test this hypothesis. Using this methodology, we investigated the 3D morphology of mitochondrial cristae in adult (3-month) and aged (2-year) murine BAT tissue via serial block face-scanning electron microscop...

The objective of this work was to ascertain whether there is a general pattern of carbon allocation and utilization in plants following herbicide supply, independent of the site of application: sprayed on the leaves or supplied to the nutrient solution. The herbicides studied were the amino acid biosynthesis-inhibiting herbicides (ABIH): glyphosate, an inhibitor of aromatic amino acid biosynthesis, and imazamox, an inhibitor of branched-chain amino acid biosynthesis. All treated plants showed impaired carbon metabolism. Carbohydrate accumulation was detected in both the leaves and roots of the treated plants. The accumulation in the roots was due to a lack of utilization of available sugars as growth was arrested, which elicited soluble carbohydrate accumulation in the leaves due to a decrease in sink strength. Under aerobic conditions, the ethanol fermentative metabolism was enhanced in the roots of the treated plants. This fermentative response was not related to a change in the t...