title: Covalent affinity labeling of the formyl peptide chemotactic receptor.
abstract: The formyl peptide chemotactic receptor present on human neutrophil membranes has been covalently affinity-labeled using three different techniques. N-Formyl-Nle-Leu-Phe-Nle-125I-Tyr-Lys was cross-linked to the receptor with dimethyl suberimidate, N-formyl-Nle-Leu-Phe-Nle-125I-Tyr-Lys-Nepsilon-4-azido-2-nitrophenyl was cross-linked by photoactivation, and N-formyl-Nle-Leu-Phe-Nle-125I-Tyr-Lys-Nepsilon-bromoacetyl reacted spontaneously with the receptor. With each method, a polypeptide which migrated as a broad band on sodium dodecyl sulfate-polyacrylamide electrophoresis, with an apparent molecular weight between 55,000 and 70,000, was specifically labeled. A dose-response curve for inhibition of covalent cross-linking of the formyl peptide derivatives by unlabeled N-formyl-Nle-Leu-Phe-Nle-Tyr-Lys correlated closely with a dose-response curve for inhibition of binding of the same formyl peptide derivatives to the receptor. The nonformylated analog, Nle-Leu-Phe-Nle-Tyr-Lys, did not inhibit binding or covalent cross-linking.
mesh_terms: D000345:Affinity Labels; D002462:Cell Membrane / Q000032:analysis; D003432:Cross-Linking Reagents; D006801:Humans; D007700:Kinetics; D008970:Molecular Weight; D009504:Neutrophils / Q000032:analysis*; D009842:Oligopeptides / Q000032:analysis*; D011485:Protein Binding; D011955:Receptors, Drug / Q000032:analysis*; D044042:Receptors, Formyl Peptide
chemical_list: D000345:Affinity Labels; D003432:Cross-Linking Reagents; D009842:Oligopeptides; D011955:Receptors, Drug; D044042:Receptors, Formyl Peptide; C021642:F-chemotactic peptide