کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1179491 962780 2007 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Val326 of Thermoactinomyces vulgaris R-47 amylase II modulates the preference for alpha-(1,4)- and alpha-(1,6)-glycosidic linkages
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Val326 of Thermoactinomyces vulgaris R-47 amylase II modulates the preference for alpha-(1,4)- and alpha-(1,6)-glycosidic linkages
چکیده انگلیسی

Thermoactinomyces vulgaris R-47 alpha-amylase II (TVA II) catalyzes not only the hydrolysis of alpha-(1,4)- and alpha-(1,6)-glycosidic linkages but also transglycosylation. The subsite + 1 structure of alpha-amylase family enzymes plays important roles in substrate specificity and transglycosylation activity. We focused on the amino acid residue at the 326th position based on information on the primary structure and crystal structure, and replaced Val with Ala, Ile, or Thr. The V326A mutant favored hydrolysis of the alpha-(1,4)-glycosidic linkage compared to the wild-type enzyme. In contrast, the V326I mutant favored hydrolysis of the alpha-(1,6)-glycosidic linkage and exhibited low transglycosylation activity. In the case of the V326T mutant, the hydrolytic activity was almost identical to that of the wild-type TVA II, and the transglycosylation activity was poor. These results suggest that the volume and the hydrophobicity of the amino acid residue at the 326th position modulate both the preference for glycosidic linkages and the transglycosylation activity.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics - Volume 1774, Issue 4, April 2007, Pages 443–449
نویسندگان
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