Fatty acylation of human platelet proteins: evidence for myristoylation of a 50 kDa peptide

Fatty acid acylation of platelet proteins was studied by measuring incorporation of 3H]palmitate and 3H]myristate after incubation at 37 degrees C for 4 h. About ten major radiolabeled proteins were detected after SDS-polyacrylamide gel electrophoresis and fluorography, for both fatty acids. Cleavage by hydroxylamine treatment indicated an ester bond of either palmitate or myristate to these proteins. Nevertheless, a single 50 kDa peptide was specifically modified by an amide-linked myristate. The functions of acylated proteins in platelets are still unknown, but their relation with DLPC-induced shape changes and vesicle shedding is excluded.