کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10873384 | 1074277 | 2005 | 4 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
The conserved histidine 106 of large thioredoxin reductases is likely to have a structural role but not a base catalyst function
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
دانش گیاه شناسی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The catalytic activity of selenocysteine-containing thioredoxin reductases can be mimicked by cysteine-variants if the local environment at the C-terminal redox center supports thiol activation. This concept of a linear catalytic site was challenged by structural data suggesting that the invariant residue His106 functions as a base catalyst for the dithiol-disulphide exchange reaction between enzyme and substrate. As reported here, we changed His106 to asparagine, glutamine, and phenylalanine in various C-terminal mutants of Drosophila melanogaster thioredoxin reductase. The catalytic activity dropped considerably, yet pH-profiles did not reveal differences, rendering a function for His106 as a base catalyst unlikely. Interestingly, the phenylalanine-mutants, designed as negative controls were the most active mutants which suggests rather a structural role of His106.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: FEBS Letters - Volume 579, Issue 3, 31 January 2005, Pages 745-748
Journal: FEBS Letters - Volume 579, Issue 3, 31 January 2005, Pages 745-748
نویسندگان
Judit Jacob, R. Heiner Schirmer, Stephan Gromer,