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Characterization of HMG CoA synthase activity of rat liver and CHO‐K1 cells
Author(s) -
SchnitzerPolokoff Robin,
Sinensky Michael
Publication year - 1987
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.240350203
Subject(s) - chinese hamster ovary cell , atp synthase , biochemistry , enzyme , isozyme , size exclusion chromatography , cytosol , microbiology and biotechnology , biology , hamster , chemistry , receptor
This report describes the characterization and partial purification of rat liver 3‐hydroxy‐3‐methylglutaryl coenzyme A (HMG CoA) synthase activity. A preliminary characterization of Chinese hamster ovary (CHO) cell HMG CoA synthase activity is also presented. Ion‐exchange chromatography of ammonium sulfate precipitates of rat liver cytosol indicate the existence of two isoenzymes of HMG CoA synthase. These isoenzymes are physically, catalytically, and immunologically distinct. One of these isoenzymes, peak 1, resembles mitochondrial HMG‐CoA synthase activity as evidenced by similarities in elution upon ion‐exchange chromatography, inhibition by MgCl 2 , and cross reactivity with an antibody prepared against the mitochondrial enzyme. As peak 1 activity is unstable, further purification studies were performed on peak 2 activity. Peak 2 can be further resolved into two activities (peaks 2A and 2B) by gel filtration. In contrast, CHO‐K1 cells (a permanent fibroblast line) possess only peak 2 type HMG CoA synthase activity.