کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10235650 | 45053 | 2012 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Structure-based engineering of glucose specificity in a family 10 xylanase from Streptomyces olivaceoviridis E-86
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موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Structure-based engineering of glucose specificity in a family 10 xylanase from Streptomyces olivaceoviridis E-86 Structure-based engineering of glucose specificity in a family 10 xylanase from Streptomyces olivaceoviridis E-86](/preview/png/10235650.png)
چکیده انگلیسی
Substrate specificity is one of the most important functional property of enzymes. We use family 10 xylanase from Streptomyces olivaceoviridis as a model for substrate specificity of glycoside hydrolases. Seven variants were initially designed to change the preference from xylose to glucose at substrate binding subsites â2 and â1. The known mobility of Trp at the â1 subsite and the influence of its environment, which is different in subset 1 and subset 2 family 10 enzymes, were taken into account in variant design. Q88A/R275A had the best ratio of p-nitrophenyl cellobioside vs p-nitrophenyl xylobioside hydrolyzing activity in the first series of variants. The crystal structure shows a movement of Trp274 compared to the native, as a result of loss of interaction with the long side chain of Arg275. The movement creates extra space for the hydroxymethyl of glucose, resulting in improved Km on glucose derived substrates, while the negative effect on kcat is compensated by the Q88A mutation, which also contributes to a further reduction of Km. Further mutagenesis based on the Q88A/R275A variant resulted in 5.2 times improvement compared to the wild-type p-nitrophenyl cellobioside hydrolyzing activity, which is the best improvement obtained so far for an engineered xylanase.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Process Biochemistry - Volume 47, Issue 3, March 2012, Pages 358-365
Journal: Process Biochemistry - Volume 47, Issue 3, March 2012, Pages 358-365
نویسندگان
Hitomi Ichinose, Shaghik Diertavitian, Zui Fujimoto, Atsushi Kuno, Leila Lo Leggio, Satoshi Kaneko,