一种古细菌酶的纯化及性质：嗜热栖热菌柠檬酸合酶

Purification and properties of an archaebacterial enzyme: citrate synthase from Sulfolobus solfataricus.

作者信息

Löhlein-Werhahn G, Goepfert P, Eggerer H

机构信息

Institut für Physiologische Chemie, Technischen Universität München.

出版信息

Biol Chem Hoppe Seyler. 1988 Feb;369(2):109-13. doi: 10.1515/bchm3.1988.369.1.109.

DOI:10.1515/bchm3.1988.369.1.109

PMID:3130075

Abstract

Citrate synthase from the thermoacidophilic archaebacterium Sulfolobus solfataricus was purified to homogeneity. The synthase is a dimer composed of subunits of Mr approximately equal to 40,000. The Km values of acetyl-CoA and oxalacetate are 7 microM and 20 microM, respectively. NADH (Ki = 3.5mM) and ATP (Ki = 0.36mM) are competitive inhibitors vs acetyl-CoA. The dimeric structure and the inhibition by nucleotides (ATP greater than NADH) correlate the archaebacterial enzyme to synthases from eukaryotes and Gram-positive eubacteria.

摘要

来自嗜热嗜酸古细菌嗜热栖热菌的柠檬酸合酶被纯化至同质。该合酶是一种二聚体，由分子量约为40,000的亚基组成。乙酰辅酶A和草酰乙酸的Km值分别为7微摩尔和20微摩尔。NADH（Ki = 3.5毫摩尔）和ATP（Ki = 0.36毫摩尔）是相对于乙酰辅酶A的竞争性抑制剂。二聚体结构以及核苷酸（ATP大于NADH）的抑制作用使这种古细菌酶与真核生物和革兰氏阳性真细菌的合酶相关联。