Replacement of the N alpha-blocking group in the formyl-methionyl tripeptide chemoattractant: an insight into the mode of binding at the receptor on rabbit neutrophils.

The tripeptide N alpha-carbamoyl-L-methionyl-L-leucyl-L-phenylalanine methyl ester has been synthesized in solution by classical methods and fully characterized. This compound, prepared in order to obtain a deeper insight into the mode of binding at the formyl peptide chemotactic receptor, has been tested for its ability to induce granule enzyme secretion from rabbit peritoneal neutrophils and found to be a complete agonist. These results confirm the hypothesis that a proton on the N alpha-blocking group of the tripeptide forms a hydrogen bond with an acceptor in the binding site.