Studies on Structure and Function of the Myristoyltransferase Inhibitor Peptide Displayed on Phage Surface

Site-directed mutagenesis was used to identify the critical residues and functional sequences of a potent NMT inhibitor peptide displayed on phage surface. W2A, H6N and H6R largely lowered the inhibitory activities of the mutated phages, and the activity of P3A and V4V5 right curved arrow A4A5 was also slightly reduced. However, V4V5 right curved arrow W4W5, H12N, H14N, C9S, C15S, deltaC15, deltaH14C15 and deltaC9--C15 had no obvious effect on the inhibition. These results suggest that W2, P3 and H6 are important in the peptide structure and/or the interaction with NMT, that amino acids with larger side chain are the more favorable residues between P3 and H6, and also that the sequences between C9 and C15 have no clear contribution to the inhibitory activity. In summary, the functional prptide directly related to the role of inhibition has been located between the N terminal T1 and A8 of the inhibitor peptide.