کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8344286 1541565 2010 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Enzymatic activity of methionine adenosyltransferase variants identified in patients with persistent hypermethioninemia
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Enzymatic activity of methionine adenosyltransferase variants identified in patients with persistent hypermethioninemia
چکیده انگلیسی
Methionine adenosyltransferases (MAT's) are central enzymes in living organisms that have been conserved with a high degree of homology among species. In the liver, MAT I and III, tetrameric and dimeric isoforms of the same catalytic subunit encoded by the gene MAT1A, account for the predominant portion of total body synthesis of S-adenosylmethionine (SAM), a versatile sulfonium ion-containing molecule involved in a variety of vital metabolic reactions and in the control of hepatocyte proliferation and differentiation. During the past 15 years 28 MAT1A mutations have been described in patients with elevated plasma methionines, total homocysteines at most only moderately elevated, and normal levels of tyrosine and other aminoacids. In this study we describe functional analyses that determine the MAT and tripolyphosphatase (PPPase) activities of 18 MAT1A variants, six of them novel, and none of them previously assayed for activity. With the exception of G69S and Y92H, all recombinant proteins showed impairment (usually severe) of MAT activity. Tripolyphosphate (PPPi) hydrolysis was decreased only in some mutant proteins but, when it was decreased MAT activity was always also impaired.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Molecular Genetics and Metabolism - Volume 101, Issues 2–3, October–November 2010, Pages 172-177
نویسندگان
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