Abstract
Specific leukotriene B 4 (LTB 4) receptors in human neutrophils were solubilized by treatment of “receptor fraction” membranes with the zwitterionic detergent (3-[(3-cholamidopropyl)-dimethylammonio]1-propane sulfonate (CHAPS). The soluble receptors were assayed by polyethylene glycol (PEG) precipitation coupled with Millipore filtration. The solubilized receptors retained all of the characteristics of the receptor sites in intact neutrophils. The binding of LTB 4 was rapid, reversible and stereospecific. Mathematical modeling analysis revealed biphasic binding of [ 3H] LTB 4 indicating two classes of binding sites. The high affinity binding site had a dissociation constant of 1.93 nM and B max of 281 fmoles/mg protein; the low affinity binding site had a dissociation constant of 78.92 nM and B max of 2522 fmoles/mg protein. Competitive binding experiments with structural analogs of LTB 4 demonstrate that the interaction between LTB 4 and its binding site is stereospecific and correlates with the relative biological activity of the analogs. These data suggest that it may be possible to purify the LTB 4 receptor from human neutrophil membranes.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call