Molecular identification of ω-amidase, the enzyme that is functionally coupled with glutamine transaminases, as the putative tumor suppressor Nit2

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• 作者：Sté ; phane Jaisson ; Maria Veiga-da-Cunha ; Emile Van Schaftingen
• 关键词：ω ; -Amidase ; Nitrilase 2 ; α ; -Ketoglutaramate ; Glutamine transaminases
• 刊名：Biochimie
• 出版年：2009
• 出版时间：September 2009
• 年：2009
• 卷：91
• 期：9
• 页码：1066-1071
• 全文大小：460 K

文摘

Our purpose was to identify the sequence of ω-amidase, which hydrolyses the amide group of α-ketoglutaramate, a product formed by glutamine transaminases. In the Bacillus subtilis genome, the gene encoding a glutamine transaminase (mtnV) is flanked by a gene encoding a putative ‘carbon-nitrogen hydrolase’. The closest mammalian homolog of this putative bacterial ω-amidase is ‘nitrilase 2’, whose size and amino acid composition were in good agreement with those reported for purified rat liver ω-amidase. Mouse nitrilase 2 was expressed in Escherichia coli, purified and shown to catalyse the hydrolysis of α-ketoglutaramate and other known substrates of ω-amidase. No such activity was observed with mouse nitrilase 1. We conclude that mammalian nitrilase 2 is ω-amidase.