کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9914921 | 1551016 | 2005 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Coenzyme specificity in fungal 17β-hydroxysteroid dehydrogenase
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
بیولوژی سلول
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چکیده انگلیسی
The 17β-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus is an NADP(H)-dependent member of the short-chain dehydrogenase/reductase superfamily (SDR) that belongs to the cP1 classical subfamily. Here, we have created several mutants by site-directed mutagenesis, and through these we have studied the amino acid residues that are responsible for coenzyme binding and specificity. The Thr202Val and Thr202Ile mutants were inactive, thus confirming the importance of Thr202 for the appropriate orientation of the coenzyme that enables the hydride transfer. The Ala50Arg and Asn51Arg mutants had increased rates of NADPH dissociation, and thus an enhanced substrate oxidation with NADP+, while the Asn51Arg mutant also showed an increased rate of NADP+ dissociation, and thus an enhanced substrate reduction with NADPH. Addition of a negatively-charged amino acid residue at the first position after the second β-strand (Tyr49Asp) affected the coenzyme specificity and turned the enzyme into an NAD+-dependent oxidase resembling the cD1d subfamily members.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Molecular and Cellular Endocrinology - Volume 241, Issues 1â2, 28 September 2005, Pages 80-87
Journal: Molecular and Cellular Endocrinology - Volume 241, Issues 1â2, 28 September 2005, Pages 80-87
نویسندگان
Katja Kristan, Jure Stojan, Gabriele Möller, Jerzy Adamski, Tea LaniÅ¡nik Rižner,