title: Characterization of an oligopeptide chemoattractant receptor on human blood monocytes using a new radioligand.
abstract: The study of chemoattractant receptors on human monocytes had been limited by the lack of a radioligand suitable for use with the small numbers of cells routinely available from human donors. A new synthetic oligopeptide radioligand f[35S]met-leu-phe, with a higher specific radioactivity than was available with the tritiated compound, was used to characterize a chemoattractant receptor on freshly isolated human blood monocytes. These cells bind f[35S]met-leu-phe with a dissociation constant (KD) of 30.2 +/- 5.6 nM and contain 84,000 +/- 11,300 receptors per cell. f[35S]met-leu-phe does not bind specifically to blood lymphocytes. The specificity of the oligopeptide receptor on monocytes is indistinguishable from the oligopeptide chemoattractant receptor on human polymorphonuclear leukocytes. Using f[35S]met-leu-phe, it will now be feasible to study the chemotactic peptide receptor on small numbers of partially purified peripheral blood monocytes from patients with defects of immune function.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D006168:Guinea Pigs; D006801:Humans; D009000:Monocytes / Q000378:metabolism*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000378:metabolism; D009504:Neutrophils / Q000378:metabolism; D009842:Oligopeptides / Q000097:blood*; D011869:Radioligand Assay; D011956:Receptors, Cell Surface / Q000032:analysis*; D044042:Receptors, Formyl Peptide; D013462:Sulfur Radioisotopes; D014316:Tritium
chemical_list: D009842:Oligopeptides; D011956:Receptors, Cell Surface; D044042:Receptors, Formyl Peptide; D013462:Sulfur Radioisotopes; D014316:Tritium; D009240:N-Formylmethionine Leucyl-Phenylalanine