Spasmogenic activity of chemotactic N-formylated oligopeptides: identity of structure--function relationships for chemotactic and spasmogenic activities.

Abstract

The chemotactic N-formylated oligopeptides are potent spasmogenic agents for guinea pig ileum. Structure-activity studies with various N-formylated peptides suggest the presence of a specific receptor that resembles in specificity the formyl peptide receptor on leukocytes. A competitive antagonist of the formyl peptide receptor on leukocytes also inhibits formyl peptideinduced ileum contraction, whereas the antihistamine diphenhydramine is without effect. The contractile response caused by the synthetic N-formylated peptides differs from those induced by acetylcholine, histamine, and substance P. In particular, a latent period after treatment with the N-formyl peptides is seen before the onset of the response, and a sustained contractile response is not maintained. In addition, tachyphylaxis does occur, but complete recovery of activity is seen after a 20-to 30-min rest period. These observations suggest broad biological roles of prokaryotic signal peptides from bacteria as acute inflammatory mediators.N-formylmethionyl peptides are potent chemotactic agents for both neutrophils (PMN) and macrophages (1) and are believed to be the analogues of the naturally occurring NH2-terminal signal peptides produced by bacteria (2, 3). These products may be responsible for the accumulation of the acute inflammatory cells in tissues containing bacteria. The binding of these bacterial peptides to specific receptors on inflammatory cells triggers a number of biological responses such as aggregation, superoxide production, enzyme secretion, and chemotaxis (4-7). Histamine release from the basophil also can occur (8).The broad range of biological responses induced by these bacterial products is similar to the effects ofC5a, a complementderived anaphylatoxin, which appears to play a major role in mediating acute inflammatory reactions. In addition to having a variety of biological effects on the neutrophil (e.g., chemotaxis, aggregation, enzyme secretion, and superoxide production), C5a also possesses potent spasmogenic activity for smooth muscle derived either from the small intestine or from the lung (9-12).The current studies were designed to determine ifchemotactic formyl oligopeptides have spasmogenic activity for smooth muscle. As defined by guinea pig ileum contraction (13, 14), we will show that the formyl peptides are potent spasmogenic agents. Furthermore, structure-activity studies with various Nformylated peptides support the possibility that the contractile response results from the binding of the formyl peptides to a specific receptor.MATERIALS AND METHODS The N-formylated peptides used were: fMet-Leu-Phe from Sigma; fNle-Leu-Phe (Nle, norleucine), Met-Leu-Phe, fMetLeu-Phe-Phe, fMet-Leu-Glu, and fMet-Abu-Phe (Abu, aaminobutyric acid) from R. Freer (Dept. of Pharmacology, Medical College of Virginia, Richmond, VA); and Boc-PheLeu-Phe-Leu-Phe (Boc, tert-butoxycarbonyl) from Peninsula Laboratories (Belmont, CA). Substance P, acetylcholine, histamine, and diphenhydramine were purchased from Sigma.The terminal g...

Broad immunocytochemical localization of the formylpeptide receptor in human organs, tissues, and cells

“…FPR immunoreactivity on human spermatozoa agrees with the reports of fMLF-induced chemotaxis of bull and human spermatozoa (Iqbal et al 1980;Gnessi et al 1986), and with specific binding of radiolabeled fMLF to human sperm (Gnessi et al 1986;Ballestras et al 1988). The ability of fMLF to cause specific contraction of the guinea pig ileum (Marasco et al 1983) is in accord with the staining of smooth muscle cells in the ileum and strongly suggests that the receptor on the smooth muscle cells responds functionally to stimulation with fMLF. This is supported by the unpublished demonstration by Dr. Jack Grider that isolated single cells from pig smooth muscle cells contract upon the addition of fMLF.…”

Stimulation of chloride secretion by N‐formyl‐methionylleucylphenylalanine (FMLP) in rabbit ileal mucosa.

“…The chemotactic response of rabbit neutrophils to FMLP is well established as being mediated through the interaction of the peptide with a specific receptor (Becker, 1979;Freer et al 1982;Becker, 1987). Because FMLP has also been observed to exert physiological effects on other cells and tissues (Iqbal, Shijav, Vijayasarathy & Balaram, 1980;Marasco et al 1982;Armour, Black, Johnson, Vincec & Berend, 1986), it has been suggested that there are non-leukocyte formylpeptide receptors (Becker, 1987).…”

“…N-Formyl-methionylleucylphenylalanine (FMLP) is a synthetic analogue of naturally occurring bacterial peptides that stimulate chemotaxis in neutrophils (Showell, Freer, Zigmond, Schiffman, Aswanikumar, Cocoran & Becker, 1976). Binding of these peptides to specific receptors on neutrophils prompts a host of responses including aggregation, superoxide production and enzyme secretion (Williams, Synderman, Pike & Leftowitz, 1977;Synderman & Fudman, 1980) and stimulation of spasmogenic activity in smooth muscle of guinea-pig ileum (Marasco, Fantone & Ward, 1982). In the guinea-pig ileum, the contractile response to FMLP is not inhibited by the H1 antagonist, diphenhydramine, and has characteristics which are different to the contractile response induced by acetylcholine, histamine or substance P (Marasco et al 1982).…”

“…Binding of these peptides to specific receptors on neutrophils prompts a host of responses including aggregation, superoxide production and enzyme secretion (Williams, Synderman, Pike & Leftowitz, 1977;Synderman & Fudman, 1980) and stimulation of spasmogenic activity in smooth muscle of guinea-pig ileum (Marasco, Fantone & Ward, 1982). In the guinea-pig ileum, the contractile response to FMLP is not inhibited by the H1 antagonist, diphenhydramine, and has characteristics which are different to the contractile response induced by acetylcholine, histamine or substance P (Marasco et al 1982). The chemotactic peptides do not appear to be able to cross the gut wall under normal conditions (Woodhouse, Anderson, Myers, Broom, Hobson & Chadwick, 1987).…”

The First Fifty Years in Research

“…In subsequent years, we were able to prove that N-formyl-Met-Leu-Phe was the active peptide in cultures of Escherichia coli and that receptors for this peptide were present on leukocytes (32)(33)(34)(35). During my nine years in Farmington, I participated in a research project that focused on the role of oxidants in acute and progressive lung injury (36)(37)(38)(39)(40) The studies also demonstrated that high levels of these products in lungs can cause intense injury and destruction of alveolar epithelial cells, sometimes resulting in the rapid onset of pulmonary fibrosis (36).…”