Mitchell C G, Anderson S C, el-Mansi E M
Department of Biological Sciences, Napier University, Edinburgh, U.K.
Biochem J. 1995 Jul 15;309 ( Pt 2)(Pt 2):507-11. doi: 10.1042/bj3090507.
Two types of citrate synthase (CS) have been purified from Pseudomonas aeruginosa, a 'large' form (CSI) and a 'small' form (CSII). The M(r)s of the CSI and CSII isoenzymes were determined to be 240,000 +/- 16,000 (mean +/- S.E.M.) and 80,300 +/- 3800 respectively. Chemical cross-linking of the native enzymes with either dimethyl suberimidate or glutaraldehyde followed by electrophoretic analysis by SDS/PAGE showed that CSI is a hexamer and CSII is a dimer. SDS/PAGE showed that CSI and CSII each consist of a single subunit type, of M(r) 42,000 +/- 2000 and M(r) 36,500 +/- 2000 respectively. CSI and CSII were also shown to be distinct kinetically, immunologically and in terms of their regulatory properties. It is suggested that the CS isoenzymes are products of different structural genes.
已从铜绿假单胞菌中纯化出两种类型的柠檬酸合酶（CS），一种是“大型”形式（CSI），另一种是“小型”形式（CSII）。测定CSI和CSII同工酶的相对分子质量分别为240,000±16,000（平均值±标准误）和80,300±3800。用辛二亚氨酸二甲酯或戊二醛对天然酶进行化学交联，然后通过SDS/PAGE进行电泳分析，结果表明CSI是六聚体，CSII是二聚体。SDS/PAGE表明，CSI和CSII均由单一亚基类型组成，其相对分子质量分别为42,000±2000和36,500±2000。还表明CSI和CSII在动力学、免疫学及其调节特性方面存在差异。有人认为CS同工酶是不同结构基因的产物。
