کد مقاله کد نشریه سال انتشار مقاله انگلیسی ترجمه فارسی نسخه تمام متن
16910 42621 2016 6 صفحه PDF ندارد دانلود رایگان
عنوان انگلیسی مقاله
Isolation and divalent-metal activation of a β-xylosidase, RUM630-BX
ترجمه فارسی عنوان
جداسازی و فعال سازی فلزی دوظرفیتی یک β-xylosidase، RUM630-BX
کلمات کلیدی
GH43 β-xylosidase؛ فعال ساز دوظرفیتی فلزی؛ kcat/Km (xylotetraose) بالاترین ؛ Xylan؛ سوخت های زیستی
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بیو مهندسی (مهندسی زیستی)
چکیده انگلیسی


• GH43 β-xylosidase was isolated from a rumen metagenomic library.
• Enzyme is highly activated by Mg2+ and Mn2+ cations.
• Enzyme has the highest reported kcat/Km acting on the natural substrate xylotetraose.

The gene encoding RUM630-BX, a β-xylosidase/arabinofuranosidase, was identified from activity-based screening of a cow rumen metagenomic library. The recombinant enzyme is activated as much as 14-fold (kcat) by divalent metals Mg2+, Mn2+ and Co2+ but not by Ca2+, Ni2+, and Zn2+. Activation of RUM630-BX by Mg2+ (t0.5 144 s) is slowed two-fold by prior incubation with substrate, consistent with the X-ray structure of closely related xylosidase RS223-BX that shows the divalent-metal activator is at the back of the active-site pocket so that bound substrate could block its entrance. The enzyme is considerably more active on natural substrates than artificial substrates, with activity (kcat/Km) of 299 s−1 mM−1 on xylotetraose being the highest reported.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Enzyme and Microbial Technology - Volume 82, January 2016, Pages 158–163
نویسندگان
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