title: Ovine platelet factor 4: purification, amino acid sequence, radioimmunoassay and comparison with platelet factor 4 of other species.
abstract: A simple method of purification of ovine platelet factor 4 (PF4) is described. Material released by freezing and thawing suspension of washed sheep platelets was fractionated by heparin-agarose chromatography and reverse phase HPLC. Purified ovine PF4 contained 85 amino acids (Mr 9130) and showed 78% homology with bovine PF4, 76% with porcine PF4, 71% homology with human PF4, and 61% with rat PF4. The heparin binding site of ovine PF4 localized in the C-terminal region of the molecule was identified as LYKKIIKRLL. The content of PF4 determined by radioimmunoassay was 22.6 (+/- 1.6 S.D.) micrograms per 10(9) platelets and 46.8 (+/- 19.6 S.D.) ng per ml platelet poor plasma collected in acid citrate dextrose in the presence of prostaglandin E1. PF4 was rapidly released during stimulation of ovine platelets by collagen.
authors.affiliation: Department of Surgery, University of Pennsylvania, Philadelphia 19104.
authors.forename: O
authors.initials: O
authors.lastname: Shigeta
authors.forename: W Q
authors.initials: WQ
authors.lastname: Lu
authors.forename: J C
authors.initials: JC
authors.lastname: Holt
authors.forename: L H
authors.initials: LH
authors.lastname: Edmunds
authors.forename: S
authors.initials: S
authors.lastname: Niewiarowski
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle / Q000235:genetics; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D002951:Citrates / Q000494:pharmacology; D019343:Citric Acid; D008969:Molecular Sequence Data; D010314:Partial Thromboplastin Time; D010978:Platelet Factor 4 / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D011863:Radioimmunoassay; D051381:Rats / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D012756:Sheep / Q000097:blood* / Q000235:genetics; D013045:Species Specificity; D013552:Swine / Q000235:genetics
chemical_list: D002951:Citrates; D019343:Citric Acid; D010978:Platelet Factor 4