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Effect of bovine serum albumin on monoacyl‐ and diacylglycerol 3‐phosphate formation in mitochondrial and microsomal fractions of rabbit hearts
Author(s) -
ZarorBehrens Gloria,
Joe Kako K.
Publication year - 1976
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02533043
Subject(s) - microsome , albumin , diacylglycerol kinase , acylation , bovine serum albumin , chemistry , acyl coa , biochemistry , chromatography , enzyme , protein kinase c , catalysis
The formation of monoacyl‐ and diacylglycerol 3‐phosphate (P) by rabbit heart mitochondrial and microsomal fractions was studied by varying the concentration of acyl‐CoA and that of bovine serum albumin in the assay system. The two subcellular fractions were prepared by the conventional differential centrifugation technique. The optimal concentration of acyl‐CoA for both mitochondrial and microsomal acylation of glycerol 3‐P was shifted to a higher range of acyl‐CoA concentrations by greater amounts of albumin. A similar shift in the acyl‐CoA concentration‐enzyme activity relationship was observed in the acylation reaction of 1‐palmitoylglycerol 3‐P by the heart microsomes. The addition of albumin increased slightly the rate of diacylglycerol 3‐P accumulation but increased greatly the rate of monoacylglycerol 3‐P accumulation at any concentration of acyl‐CoA; the effect was observed with mitochondrial or microsomal fraction as the crude enzyme source. Moreover, palmitoyl‐CoA and linoleoyl‐CoA served equally well as the acyl donor for the acylation reaction. However, relatively more monoacyl‐ than diacylglycerol 3‐P was accumulated in the assays with rabbit heart mitochondrial fraction in the presence of albumin, whereas more diacylthan monoacyglycerol 3‐P was formed by the microsomal fraction. As a result, the microsomal diacyl: monoacyl‐glycerol 3‐P ratio was invariably greater than the mitochondrial ratio at a given concentration of acyl‐CoA and albumin.