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
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
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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 15Â 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 2â3, OctoberâNovember 2010, Pages 172-177
Journal: Molecular Genetics and Metabolism - Volume 101, Issues 2â3, OctoberâNovember 2010, Pages 172-177
نویسندگان
JoaquÃn Fernández-Irigoyen, Enrique SantamarÃa, Yin-Hsiu Chien, Wuh-Liang Hwu, Stanley H. Korman, Hanna Faghfoury, Andreas Schulze, George E. Hoganson, Sally P. Stabler, Robert H. Allen, Conrad Wagner, S. Harvey Mudd, Fernando J. Corrales,