绿头鸭疟原虫的丝氨酸羟甲基转移酶

The serine hydroxymethyltransferase of Plasmodium lophurae.

作者信息

Platzer E G, Campuzano H C

出版信息

J Protozool. 1976 May;23(2):282-6. doi: 10.1111/j.1550-7408.1976.tb03770.x.

DOI:10.1111/j.1550-7408.1976.tb03770.x

Abstract

Plasmodium lophurae serine hydroxymethyltransferase (EC 2.1.2.1) was partially purified and characterized by (NH4)2SO4 fractionation and chromatography on Sephadex G-100. The enzyme, precipitated by 3.0.3.3 M (NH4)2SO4, had a molecular weight of 68,300 as estimated by exclusion chromatography on G-100. The pH optimum of the enzyme was 6.8-7.6 in sodium phosphate-citrate buffer. Citrate stabilized the enzyme during storage in phosphate buffer at 4 C. The Km was 4.3 X 10(-3) M for L-serine and 2.5 X 10(-4) M for tetrahydrofolate.

摘要

绿头鸭疟原虫丝氨酸羟甲基转移酶（EC 2.1.2.1）通过硫酸铵分级分离和葡聚糖凝胶G - 100柱层析进行了部分纯化和特性鉴定。该酶在3.0.3.3 M硫酸铵中沉淀，通过G - 100凝胶过滤层析估计其分子量为68,300。在磷酸钠 - 柠檬酸盐缓冲液中，该酶的最适pH为6.8 - 7.6。柠檬酸盐在4℃的磷酸盐缓冲液中储存期间可稳定该酶。L - 丝氨酸的米氏常数为4.3×10⁻³ M，四氢叶酸的米氏常数为2.5×10⁻⁴ M。