A simplified assay for the enzyme responsible for the attachment of myristic acid to the N-terminal glycine residue of proteins, myristoyl-CoA: glycylpeptide N-myristoyltransferase.

A greatly simplified assay for myristoyl-CoA:glycylpeptide N-myristoyltransferase (NMT) activity is described. The assay is based on the differential solubility of the acyl-peptides produced as a consequence of the NMT activity and yields results comparable with those obtained with the original assay described by Towler & Glaser [(1986) Proc. Natl. Acad. Sci. U.S.A. 83, 2812-2816], which requires h.p.l.c. to determine the production of the acyl-peptides. The use of the revised assay in the preliminary steps of the purification of rat brain NMT is described, and its use in determining the fatty acid-specificity of the enzyme is illustrated. The results are shown to be comparable with those obtained with the h.p.l.c.-based assay.