Structures and high and low affinity ligand binding properties of murine type I and type II macrophage scavenger receptors.

摘要: Macrophage scavenger receptors have been implicated in various macrophage-associated processes, including atherosclerosis and clearance of bacterial endotoxin. They bind to a wide variety polyanionic ligands display complex binding characteristics. cDNAs from the murine macrophage-like cell line P388D1 encoding full-length type I II were cloned, sequenced, expressed Chinese hamster ovary cells. A fragment corresponding genomic DNA was also partially positions cloned intron/exon boundaries determined. Comparisons receptors' sequences with bovine, rabbit, human used refine multidomain model these trimeric, fibrous, membrane receptors. Metabolic labeling/immunoprecipitation experiments showed that most macrophage receptor protein by cells N-glycosylated receptor; only small amounts detected. Analysis properties provided evidence such differential expression forms may functional significance. There substantial receptor-type (I vs. II), as well receptor-species (bovine murine), differences inhibition 125I-labeled AcLDL (acetylated low density lipoprotein) ReLPS, form These arose, part, because exhibited both high (Kd1(4 degrees C) = 0.05-0.2 micrograms protein/ml) (Kd2(4 2.5-12.8 affinity AcLDL. The ability ReLPS (1 mg/ml) inhibit either or two classes interactions varied depending on species receptor.