title: Evidence for serotonin binding in vitro by platelet factor 4 and beta-thromboglobulin.
abstract: Evidence is presented for in vitro high affinity binding of serotonin (5-HT) by beta-thromboglobulin (beta TG) and platelet factor 4 (PF4) from human blood. Results include: 1) identification by radioimmunoassay of PF4 in specifically bound material obtained by 5-HT affinity chromatography of human platelet extracts; 2) binding of 72% and 6% of radiolabelled PF4 on 5-HT and control affinity columns, respectively; and 3) binding of approximately 8 moles of 5-HT per mole of purified beta TG in the presence of ferrous ion and heparin in ultrafiltration studies, with Scatchard analysis indicating a dissociation constant of about 4 X 10(-8) M.
mesh_terms: D001609:Beta-Globulins / Q000378:metabolism*; D001779:Blood Coagulation Factors / Q000378:metabolism*; D002250:Carbon Radioisotopes; D002846:Chromatography, Affinity; D006801:Humans; D010978:Platelet Factor 4 / Q000378:metabolism*; D011485:Protein Binding; D011863:Radioimmunoassay; D012701:Serotonin / Q000378:metabolism*; D014462:Ultrafiltration; D001620:beta-Thromboglobulin / Q000378:metabolism*
chemical_list: D001609:Beta-Globulins; D001779:Blood Coagulation Factors; D002250:Carbon Radioisotopes; D001620:beta-Thromboglobulin; D012701:Serotonin; D010978:Platelet Factor 4