Membrane-Bound γ-Glutamyl Transpeptidase
Membrane-Bound γ-Glutamyl Transpeptidase
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膜结合 γ-谷氨酰转肽酶
DOI：
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发表时间：
1976
期刊：
影响因子：
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通讯作者：
L. Ross
中科院分区：
文献类型：
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作者：
A. Meister;S. Tate;L. Ross
γ-谷氨酰转肽酶是一种膜结合酶，催化谷胱甘肽(和其他γ-谷氨基化合物)的γ-谷氨酰基部分转移到氨基酸(和肽)受体上，如反应(1)所示：
$$谷胱甘肽+α-谷氨酰基、α-谷氨酰基、α-谷氨酰基+半胱氨酸基、甘氨酸
(1)
这一反应是谷胱甘肽代谢途径的第一步，推测该反应或类似反应参与氨基酸的运输。因此，γ-谷氨酰转肽酶通过与细胞外氨基酸和细胞内谷胱甘肽(或其他含有γ-谷氨基载体的化合物)相互作用，介导氨基酸跨细胞膜的转运；根据这一想法，氨基酸以γ-谷氨酰氨基酸的形式进入细胞。
γ-Glutamyl transpeptidase is a membrane-bound enzyme that catalyzes the transfer of the γ-glutamyl moiety of glutathione (and of other γ-glutamyl compounds) to amino acid (and peptide) acceptors as indicated in reaction (1):
$$ glutathione + a\min o\,acid \to \gamma - glutamyl\,a\min o\,acid + cysteinyl\,glycine $$
(1)
This reaction is the first step in a quantitatively significant pathway of glutathione metabolism, and it has been postulated that this or analogous reactions are involved in amino acid transport. Thus, γ-glutamyl transpeptidase mediates the translocation of the amino acid across the cell membrane by interacting with both extracellular amino acid and intracellular glutathione (or other compounds that contain the γ-glutamyl carrier); according to this idea, the amino acid enters the cell as a γ-glutamyl amino acid.