一种来自牛红细胞的ADP核糖基转移酶，显然对半胱氨酸残基具有特异性。

An ADP-ribosyltransferase from bovine erythrocytes apparently specific for cysteine residues.

作者信息

van Heyningen S, Saxty B A

机构信息

Department of Biochemistry, University of Edinburgh, Great Britain.

出版信息

Adv Exp Med Biol. 1997;419:275-8. doi: 10.1007/978-1-4419-8632-0_36.

DOI:10.1007/978-1-4419-8632-0_36

PMID:9193666

Abstract

An NAD+:cysteine glycohydrolase purified from bovine erythrocytes had a specific activity of 1900 (nmol nicotinamide released).min-1.mg-1, a K(m) for cysteine of 4.0 mM, and an M, of 45,000. The enzyme also catalysed the dose-dependent ADP-ribosylation of several bovine erythrocyte proteins, including a doublet of high M(r) and proteins of M(r) 60,000, 55,000, and 29,000. ADP-ribosylation of the M(r) 55,000 protein was blocked by pre-treatment of the erythrocyte membranes with N-ethylmaleimide, and ADP-ribose was released by treatment with mercuric ions, but not with hydroxylamine. The enzyme therefore appears to be a cysteine-specific ADP-ribosyltransferase.

摘要

从牛红细胞中纯化得到的一种NAD⁺：半胱氨酸糖水解酶，其比活性为1900（每分钟释放的烟酰胺纳摩尔数）·分钟⁻¹·毫克⁻¹，半胱氨酸的K(m)为4.0 mM，分子量为45,000。该酶还能催化几种牛红细胞蛋白的剂量依赖性ADP核糖基化反应，包括一个高分子量的双峰以及分子量为60,000、55,000和29,000的蛋白。用N-乙基马来酰亚胺预处理红细胞膜可阻断分子量为55,000蛋白的ADP核糖基化反应，用汞离子处理可释放ADP核糖，但用羟胺处理则不能。因此，该酶似乎是一种半胱氨酸特异性ADP核糖基转移酶。