Solubilization and characterization of leukotriene B4 receptor-GTP binding protein complex from porcine spleen.
A high amount of leukotriene B4 (LTB4) binding protein was observed in the porcine spleen. It was solubilized and partially purified from spleen membrane with 3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate (CHAPS). Scatchard analysis indicated the presence of a single class of receptor with Kd and Bmax values of 0.26 nM and 120 fmol/mg protein, respectively. The receptor was specific for LTB4, and Ki values for 20-hydroxy- and 20-carboxy-LTB4, both inactive metabolites of LTB4, were 1.7 nM and over 1,000 nM, respectively. By the addition of 10 microM GTP gamma S, a low affinity binding site appeared with a Kd value of 390 nM. A pretreatment of the receptor-GTP binding protein complex with islet-activating protein (IAP) increased the inhibitory effect of GTP gamma S on LTB4 binding, indicating that the LTB4 receptor is coupled with an IAP-sensitive GTP-binding protein in the porcine spleen.
Miki
I
I
Department of Physiological Chemistry and Nutrition, Faculty of Medicine, University of Tokyo, Japan.
Watanabe
T
T
Nakamura
M
M
Seyama
Y
Y
Ui
M
M
Sato
F
F
Shimizu
T
T
D000818:Animals; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000302:isolation & purification* / Q000378:metabolism; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D007700:Kinetics; D007975:Leukotriene B4 / Q000378:metabolism; D046911:Macromolecular Substances; D037342:Pertussis Toxin; D011971:Receptors, Immunologic / Q000187:drug effects / Q000302:isolation & purification* / Q000378:metabolism; D018102:Receptors, Leukotriene B4; D013154:Spleen / Q000276:immunology / Q000378:metabolism*; D013552:Swine; D013873:Thionucleotides / Q000494:pharmacology; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D046911:Macromolecular Substances; D011971:Receptors, Immunologic; D018102:Receptors, Leukotriene B4; D013873:Thionucleotides; D010566:Virulence Factors, Bordetella; D007975:Leukotriene B4; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins