Ligand-induced formation of the leukotriene B4 receptor-G protein complex of human polymorphonuclear leukocytes

✍ Scribed by Jeffrey W. Sherman; Michelle A. Mendelson; John M. Boggs; Catherine H. Koo; Dr. Edward J. Goetzl

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 515 KB
• Volume: 48
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.240480405

✦ Synopsis

The components of the polymorphonuclear leukocyte (PMNL) receptor for leukotriene B , (LTB,) were examined by Sephacryl S-300 exclusion chromatography of PMNL membrane proteins, which were solubilized before and after the binding of [3H] LTB,. When the PMNL membranes were solubilized in 3-[(3-cholamidopropyI)dimethylammoniol-I -propanesulfonate (CHAPS) and filtered on Sephacryl S-300 prior to addition of [3H] LTB,, the binding activity was associated with a 65 kD protein. In contrast, the radioactivity of [3H] LTB, bound to PMNL membranes prior to solubilization was recovered predominately with a 140 kD protein. When PMNL membranes had been pretreated with pertussis toxin, but not cholera toxin, before the addition of LTB, and subsequent solubilization, radioactivity was recovered predominately with the 65 kD protein. The addition of guanylylimidodiphosphate (GMP-PNP), a nonhydrolyzable derivative of guanosine triphosphate (GTP), to PMNL membrane receptors bearing [3H] LTB, either prior to or after CHAPS solubilization reduced the yield of the 140 kD presumed LTB, receptor protein-G protein complex. That the maximum specific binding of [35Sl guanosine-5'-0-3-thiotriphosphate (GTP-gammas) to LTB,-binding proteins in the Sephacryl S-300 effluent corresponded to the 140 kD protein supported the presence of a G protein in the LTB, receptor complex.