کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6489537 1416538 2018 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Active site pocket of Streptomycesd-stereospecific amidohydrolase has functional roles in aminolysis activity
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
Active site pocket of Streptomycesd-stereospecific amidohydrolase has functional roles in aminolysis activity
چکیده انگلیسی
d-Stereospecific amidohydrolase from Streptomyces sp. 82F2 (DAH) recognizes d-amino acyl ester derivatives as substrates and catalyzes hydrolysis and aminolysis to yield d-amino acids and d-amino acyl peptides or amide derivatives, respectively. Crystallographic analysis has revealed that DAH possesses a large cavity with a small pocket at the bottom. Because the pocket is close to the catalytic center and is thought to interact with substrates, we examined the function of the eight residues that form the pocket in terms of substrate recognition and aminolysis via mutational analysis. Formation of the acyl-enzyme intermediate and catalysis of aminolysis by DAH were changed by substitutions of selected residues with Ala. In particular, I338A DAH exhibited a significant increase in the condensation product of Ac-d-Phe methyl ester and 1,8-diaminooctane (Ac-d-Phe-1,8-diaminooctane) compared with the wild-type DAH. A similar effect was observed by the mutation of Ile338 to Gly and Ser. The pocket shapes and local flexibility of the mutants I338G, I338A, and I338S are thought to resemble each other. Thus, changes in the shape and local flexibility of the pocket of DAH by mutation presumably alter substrate recognition for aminolysis.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Bioscience and Bioengineering - Volume 126, Issue 3, September 2018, Pages 293-300
نویسندگان
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