title: Characterization of the human C1q receptor.
abstract: At the meeting new procedures were reported for the isolation of the receptor which binds to the collagen-stalks of C1q, a subcomponent to the macromolecular complex, C1. The C1q-receptor was isolated from human tonsil cells, by a two-step procedure which did not involve affinity chromatography on C1q-Sepharose. In solution the C1q-receptor from tonsil cells behaved as an elongated dimer of two approx. 60 kDa chains. A C1q-receptor preparation isolated from human phagocytes, using pepsin-digested C1q for affinity chromatography, was found to be predominantly a molecule of approx. 120 kDa as assessed by SDS-PAGE. The amino acid compositions of C1q-receptor preparations derived from Raji (B-lymphoblastoid) and U937 (monocytic) cell-lines were found to be very similar. These results suggest that the human C1q-receptor may be a one-chain molecule, and also raise the possibility that there is more than one type of C1q receptor on cell surfaces.
authors.affiliation: Department of Immunology, L. Eötvös University, Göd, Hungary.
authors.forename: A
authors.initials: A
authors.lastname: Erdei
authors.forename: K B
authors.initials: KB
authors.lastname: Reid
mesh_terms: D000596:Amino Acids / Q000032:analysis; D001402:B-Lymphocytes / Q000032:analysis; D002352:Carrier Proteins; D002460:Cell Line; D002846:Chromatography, Affinity; D015922:Complement C1q; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D018960:Hyaluronan Receptors; D008562:Membrane Glycoproteins; D024101:Mitochondrial Proteins; D015394:Molecular Structure; D008970:Molecular Weight; D009000:Monocytes / Q000032:analysis; D014066:Palatine Tonsil / Q000032:analysis; D011951:Receptors, Complement / Q000302:isolation & purification*
chemical_list: D000596:Amino Acids; C087299:C1QBP protein, human; D002352:Carrier Proteins; D018960:Hyaluronan Receptors; D008562:Membrane Glycoproteins; D024101:Mitochondrial Proteins; D011951:Receptors, Complement; C032402:complement 1q receptor; D015922:Complement C1q