Acylated proteins in Acholeplasma laidlawii

The covalent modification of membrane proteins by long-chain fatty acids was determined in two strains of Acholeplasma laidlawii by one-dimensional gel electrophoresis of radiolabeled membranes. Of the more than 50 membrane polypeptides detected, approximately 30 were labeled with [3H]palmitate, whereas covalent binding of [3H]oleate to membrane proteins could not be demonstrated. We suggest that in these wall-less bacteria, membrane protein acylation with saturated fatty acids may serve to ensure the structural integrity of the membrane.