甲状腺可溶性5'-核苷酸酶的部分纯化及性质

Soluble 5'-nucleotidase from thyroid gland partial purification and properties.

作者信息

Niedźwiecka J, Jaroszewicz L

机构信息

Department of Physical Chemistry, Medical Acedemy, Bialystok, Poland.

出版信息

Biochem Biophys Res Commun. 1996 Apr 16;221(2):471-6. doi: 10.1006/bbrc.1996.0619.

DOI:10.1006/bbrc.1996.0619

PMID:8619879

Abstract

A soluble 5'-nucleotidase from pig thyroid was purified over 110-fold by chromatography on phosphocellulose, (NH4)2SO4 precipitation and gel filtration on Sephadex G-150. The purified 5-nucleotidase was free of non-specific phosphatases. The enzyme had optimum pH at 6.5 and hydrolysed preferentially IMP and GMP. The Km values were 0.66 and 1.0 mM for IMP and GMP, respectively. The enzyme also hydrolysed other nucleotides and showed the following relative Vmax:IMP>CMP>AMP>UMP.Mg2+ was necessary for the enzyme activity.

摘要

通过磷酸纤维素柱层析、硫酸铵沉淀及Sephadex G - 150凝胶过滤，从猪甲状腺中纯化出一种可溶性5'-核苷酸酶，纯化倍数超过110倍。纯化后的5-核苷酸酶不含非特异性磷酸酶。该酶的最适pH为6.5，优先水解肌苷酸（IMP）和鸟苷酸（GMP）。IMP和GMP的米氏常数（Km）分别为0.66 mM和1.0 mM。该酶也能水解其他核苷酸，其相对最大反应速度（Vmax）如下：IMP > CMP > AMP > UMP。镁离子（Mg2+）是该酶活性所必需的。