PMID: 8454590Mar 25, 1993Paper

Modification of sulfhydryl groups of interleukin-8 (IL-8) receptor impairs binding of IL-8 and IL-8-mediated chemotactic response of human polymorphonuclear neutrophils.

The Journal of Biological Chemistry
A K SamantaE Ali

Abstract

Interleukin-8 (IL-8), a monocyte-derived neutrophil chemotactic agent, has a potential role in the regulation of inflammatory responses. The specific receptor for IL-8 has been identified and characterized on the surface of human neutrophils (Samanta, A. K., Oppenheim, J. J., and Matsushima, K. (1989) J. Exp. Med. 169, 1185-1189). The present study demonstrates that at least two sulfhydryl groups of this receptor from human neutrophils participate in the binding of IL-8. Incubation of neutrophils with sulfhydryl group-modifying reagents, N-ethylmaleimide and diazene dicarboxylic acid bis-N,N-dimethylamide (diamide), severely impaired the binding of 125I-IL-8 to neutrophils. Treatment with 0.8 mM N-ethylmaleimide and 0.4 mM diamide inhibit binding of 125I-IL-8 to the neutrophils by 62 and 60%, respectively. These inhibitory effects could be reversed by 84-87% by treatment with 2-4 mM dithiothreitol. The saturable amount of the ligand, IL-8, provided partial protection against the modifying reagents. N-Ethylmaleimide and diamide at a concentration of 0.4 mM reduced chemotactic migration of neutrophils in a Boyden chamber by 95 and 60%, respectively. At a concentration of 0.4 mM, N-ethylmaleimide reduced the IL-8-induced (10 micro...Continue Reading

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