Biosynthesis of fatty acids in mammary tissue: I. Purification and properties of fatty acid synthetase from lactating-goat mammary tissue

Fatty acid synthetase of a high degree of purity has been prepared from the particle-free supernatant fraction of lactating-goat mammary tissue. Ultracentrifugation and polyacrylamide gel electrophoresis revealed heterogeneity of the preparation. However, the enzyme complex was sufficiently free of malonyl-CoA decarboxylase activity to enable the demonstration of the requirement for the “primer” acyl-CoA in addition to malonyl-CoA and NADPH. The enzyme appeared to utilize butyryl-CoA more efficiently than acetyl-CoA as “primer.” The nature and extent of the fatty acids synthesized using these two “primers” were characteristically different and were pronouncedly influenced by the concentration of malonyl-CoA.