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1دورية أكاديمية
المؤلفون: Mugford, S. T., Qi, X., Bakht, S., Hill, L., Wegel, E., Hughes, R. K., Papadopoulou, K., Melton, R., Philo, M., Sainsbury, F., Lomonossoff, G. P., Roy, A. D., Goss, R. J. M., Osbourn, A.
مصطلحات موضوعية: acyltransferase, antiinfective agent, carboxypeptidase, serine carboxypeptidase, vegetable protein, amino acid sequence, article, chemistry, classification, enzymology, genetics, immunoblotting, innate immunity, metabolism, molecular genetics, nucleotide sequence, oat, phylogeny, physiology, protein multimerization, sequence homology, Acyltransferases, Anti-Infective Agents, Avena sativa, Carboxypeptidases, Immunity, Innate, Molecular Sequence Data, Plant Proteins, Amino Acid
الوصف: Serine carboxypeptidase-like (SCPL) proteins have recently emerged as a new group of plant acyltransferases. These enzymes share homology with peptidases but lack protease activity and instead are able to acylate natural products. Several SCPL acyltransferases have been characterized to date from dicots, including an enzyme required for the synthesis of glucose polyesters that may contribute to insect resistance in wild tomato (Solanum pennellii) and enzymes required for the synthesis of sinapate esters associated with UV protection in Arabidopsis thaliana. In our earlier genetic analysis, we identified the Saponin-deficient 7 (Sad7) locus as being required for the synthesis of antimicrobial triterpene glycosides (avenacins) and for broad-spectrum disease resistance in diploid oat (Avena strigosa). Here, we report on the cloning of Sad7 and show that this gene encodes a functional SCPL acyltransferase, SCPL1, that is able to catalyze the synthesis of both N-methyl anthraniloyl- and benzoyl-derivatized forms of avenacin. Sad7 forms part of an operon-like gene cluster for avenacin synthesis. Oat SCPL1 (SAD7) is the founder member of a subfamily of monocot-specific SCPL proteins that includes predicted proteins from rice (Oryza sativa) and other grasses with potential roles in secondary metabolism and plant defense. © 2009 American Society of Plant Biologists.
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2دورية أكاديمية
المؤلفون: Psochiou, E., Mamuris, Z., Panagiotaki, P., Kouretas, D., Moutou, K. A.
المصدر: ://WOS:000246544100002
مصطلحات موضوعية: carboxypeptidases, chymotrypsin, digestive proteases, elastase, salinity, Sparus aurata, trypsin, GILTHEAD SEA BREAM, TURBOT SCOPHTHALMUS-MAXIMUS, SALMO-SALAR L, FRESH-WATER, ENERGY-METABOLISM, PYLORIC CECA, TIME-COURSE, GROWTH, FISH, ACCLIMATION, Biochemistry & Molecular Biology, Zoology
الوصف: The response of the digestive proteases to abrupt salinity change was studied in juvenile gilthead sea bream (Sparus aurata) for 15 days after transfer from 33 parts per thousand to 21 parts per thousand. Salinity decrease affected significantly neither the activity of total acid proteases in stomach, nor the activities of total alkaline proteases and major serine proteases - trypsin and chymotrypsin - in the alkaline part of the intestine. The activity of the major proteases was significantly different between the alkaline segments of the intestine, with the posterior intestine presenting the highest activities followed by the pyloric caeca. This distribution pattern remained unaffected by salinity decrease. Notably, salinity change led to significant alterations in elastase and carboxypeptidase activity. The changes were more prominent in the upper part of the intestine (pyloric caeca and anterior intestine) than in the posterior intestine. In pyloric caeca significant alteration of carboxypeptidase A and B activities was observed, elastase changes were confined to anterior intestine together with alterations in carboxypeptidase B activity, while in posterior intestine the changes were restricted to carboxypeptidase A activity. The results are discussed in relation to the osmoregulatory action of the intestinal segments and dietary protein digestion. (C) 2007 Elsevier Inc. All rights reserved.
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