FAD-dependent malate dehydrogenase from Mycobacterium smegmatis: activation of the lipid-depleted inactive enzyme by a phospholipid analogue, di (triethyleneglycoltetradecylether) phosphate

Abstract

A novel phospholipid analogue, di (triethyleneglycol-n-tetradecylether) phosphate was synthesized and its activation ability for a phospholipid-requiring enzyme, Mycobacterium smegmatis malate dehydrogenase, was examined. The results showed that the newly-synthesized phospholipid analogue a high ability, nearly equal to that of natural beef heart cardiolipin, for the activation of the lipid-depleted inactive enzyme; whereas both simple di-n-octylphosphate and di-n-tetradecylphosphate were found to have poor activation abilities. These results strongly suggest that a slightly hydrophilic region between the phosphate group and the two alkyl chains of an anionic phospholipid is important for the best activation of M. smegmatis malate dehydrogenase.