ATP: Citrate Lyase - The Regulatory Enzyme for Lipid Biosynthesis in Lipomyces starkeyi?

Abstract

ATP: citrate lyase from Lipomyces starkeyi was inhibited by oleoyl-CoA (50% inhibition at approx. 3 μm) and other long-chain fatty acyl-CoA esters but not by other fatty acyl compounds. The inhibition was readily reversed by adding bovine serum albumin. The molecular size of the protein was not altered even in the presence of 200 μm-oleoyl-CoA. It is concluded that this is a genuine feedback inhibition effect which may be significant in regulating the amount of triacylglycerol being produced by an oleaginous yeast.