title: Isolation and biological properties of osteopontin from bovine milk.
abstract: A procedure for the isolation of osteopontin (OPN) from bovine milk using ion-exchange and hydrophobic chromatography is described. A DEAE-Sephacel column followed by dual phenyl-Sepharose columns yielded approximately 8 mg of purified protein per liter of milk. SDS-PAGE analysis revealed that the protein migrated at M(r) 60,000. NH2-terminal sequence analysis of the first seven amino acids revealed the protein to be identical to that previously reported for bovine OPN. Also, our preparation demonstrated expected biological properties of OPN including adhesion of both endothelial and vascular smooth muscle cells to OPN in a dose- and Arg-Gly-Asp-dependent manner. Furthermore, OPN coupled to Sepharose was capable of binding the alpha v beta 3 integrin from a detergent extract of endothelial cells. Thus, our procedure yielded biologically active OPN from an abundant and natural source.
authors.affiliation: Microcirculation Research Institute, Texas A&M University Health Science Center, Texas A&M University, College Station 77843-1114, USA.
authors.forename: K J
authors.initials: KJ
authors.lastname: Bayless
authors.forename: G E
authors.initials: GE
authors.lastname: Davis
authors.forename: G A
authors.initials: GA
authors.lastname: Meininger
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D002845:Chromatography / Q000379:methods; D002847:Chromatography, Agarose; D002852:Chromatography, Ion Exchange; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects; D005260:Female; D006801:Humans; D008892:Milk / Q000737:chemistry*; D008970:Molecular Weight; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects; D009842:Oligopeptides / Q000737:chemistry; D053495:Osteopontin; D051381:Rats; D019030:Receptors, Vitronectin / Q000378:metabolism; D012685:Sepharose / Q000031:analogs & derivatives; D012795:Sialoglycoproteins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D009842:Oligopeptides; D019030:Receptors, Vitronectin; C506895:SPP1 protein, human; D012795:Sialoglycoproteins; C506897:Spp1 protein, rat; D053495:Osteopontin; C020927:phenyl-sepharose; C047981:arginyl-glycyl-aspartic acid; D012685:Sepharose