γ-glutamyl transpeptidase, a glutathionase:: its expression and function in carcinogenesis
γ-glutamyl transpeptidase, a glutathionase:: its expression and function in carcinogenesis
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DOI：
10.1016/s0009-2797(97)00170-1
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发表时间：
1998-04-24
影响因子：
5.1
通讯作者：
Hanigan, MH
中科院分区：
文献类型：
--
作者：
Hanigan, MH
在整个植物和动物界都发现了伽马 - 谷氨酰胺转肽酶（GGT）。它是一种细胞表面糖蛋白，可裂解γ-谷氨酰胺酰胺键。酶最丰富的生理底物是谷胱甘肽和谷胱甘肽偶联化合物。 GGT启动细胞外谷胱甘肽裂解其成分氨基酸，然后可以将其转运到细胞中。它还催化了谷胱甘肽偶联化合物转化为铜氨酸的第一步。在许多人类肿瘤中，在许多致癌物诱导的动物肿瘤中，GGT在高水平上表达。这些观察结果越来越多地关注酶在肿瘤发展和治疗中的作用。本章以正常组织中GGT的结构和功能的概述开始。其表达在肿瘤组织中的表达以及GGT影响肿瘤对化学疗法的反应的方式。本章以讨论使用GGT激活和靶向化学疗法药物的策略的讨论结束，以改善对人类恶性肿瘤的治疗方法。 （c）1998 Elsevier Science Ireland Ltd.保留所有权利。
gamma-Glutamyl transpeptidase (GGT) is found throughout the plant and animal kingdoms. It is a cell surface glycoprotein that cleaves gamma-glutamyl amide bonds. The most abundant physiologic substrates for the enzyme are glutathione and glutathione-conjugated compounds. GGT initiates the cleavage of extracellular glutathione into its constituent amino acids which can then be transported into the cell. It also catalyzes the initial step in the conversion of glutathione-conjugated compounds to mercapturic acids. GGT is expressed at high levels in many human tumors and in many carcinogen-induced tumors in animals. These observations have lead an increased focus on the role of the enzyme in the development and treatment of tumors. This chapter begins with an overview of the structure and function of GGT in normal tissues. A summary of its expression in neoplastic tissues and the ways in which GGT effects the response of tumors to chemotherapy follows. The chapter concludes with a discussion of strategies for using GGT to activate and target chemotherapy drugs to tumors as a means of improving treatment for common human malignancies. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.