کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9121939 | 1159201 | 2005 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
C-terminus mutations of Acremonium chrysogenum deacetoxy/deacetylcephalosporin C synthase with improved activity toward penicillin analogs
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
ژنتیک
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چکیده انگلیسی
Deacetoxy/deacetylcephalosporin C synthase (acDAOC/DACS) from Acremonium chrysogenum is a bifunctional enzyme that catalyzes both the ring-expansion of penicillin N to deacetoxycephalosporin C (DAOC) and the hydroxylation of the latter to deacetylcephalosporin C (DAC). Three residues N305, R307 and R308 located in close proximity to the C-terminus of acDAOC/DACS were each mutated to leucine. The N305L and R308L mutant acDAOC/DACSs showed significant improvement in their ability to convert penicillin analogs. R308 was identified for the first time as a critical residue for DAOC/DACS activity. Kinetic analyses of purified R308L enzyme indicated its improved catalytic efficiency is due to combined improvements of Km and kcat. Comparative modeling of acDAOC/DACS supports the involvement of R308 in the formation of substrate-binding pocket.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: FEMS Microbiology Letters - Volume 246, Issue 1, 1 May 2005, Pages 103-110
Journal: FEMS Microbiology Letters - Volume 246, Issue 1, 1 May 2005, Pages 103-110
نویسندگان
Xiao-Bin Wu, Ke-Qiang Fan, Qin-Hong Wang, Ke-Qian Yang,