کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5522488 | 1545980 | 2017 | 9 صفحه PDF | دانلود رایگان |
Desaturases, key enzymes in the metabolism of fatty acids, regulate the physical and biochemical properties of membranes. They adjust the composition of saturated and unsaturated fatty acids in response to changes in the environmental.We demonstrated the existence of Î9 desaturase activity in epimastigotes of the Trypanosoma cruzi Tulahuen strain. In the present study, showed that this enzyme has an approximate molecular mass of 50Â kDa and a pI value of approximately 9. In order to characterize the Î9 desaturase of Trypanosoma cruzi, (TcÎ9DES) we have cloned, sequenced and expressed in Escherichia coli. The gene consists of 1300Â bp and encodes a peptide of 433 amino acids with a molecular weight of 50Â kDa. Analysis of the amino acid sequence revealed three clusters of histidine and two hydrophobic regions, characteristic of membrane-bound desaturases.Gene expression studies showed that TcÎ9DES was overexpressed as an active protein. Fatty acid analysis showed that the expressed protein was confirmed to be functional with Î9 desaturase activity. This enzyme changed the fatty acid profile of TcÎ9DES-expressing E. coli, decreasing the levels of palmitic (16:0) and stearic (18:0) acids and enhancing palmitoleic (16:1Î9) and monounsaturated 18 carbons fatty acids. When [1-14C]palmitic or [1-14C]stearic acid was used as substrate, TcÎ9DES-expressing E. coli exhibited high desaturase activity associated with increased levels of monounsaturated fatty acids, suggesting that the TcÎ9DES enzyme was actively expressed in E. coli.To check the commitment of TcÎ9DES against sterol biosynthesis inhibitors we tested the activity under ketoconazole effect. Native TcÎ9DES, showed a significant activity inhibition.Since TcÎ9DES has shown active participation under different environmental factors, among them, ketoconazole, we consider that it plays a critical role in the metabolism of the parasite
Journal: Microbiological Research - Volume 194, January 2017, Pages 29-37