title: Localization of transglutaminase-reactive glutamine residues in bovine osteopontin.
abstract: Here we report the identification of two transglutaminase-reactive glutamines (Gln-34 and Gln-36) in bovine osteopontin (OPN). Sequence alignment revealed that these glutamines are conserved in all known OPN sequences, indicating a functional importance of this region of the protein. Furthermore, immunological analysis of bovine bone demonstrated that OPN is present in high-molecular-mass complexes in vivo. These findings support the functional aspects of a transglutaminase-catalysed cross-linking of OPN in facilitating cellular attachment and tissue calcification.
authors.affiliation: Protein Chemistry Laboratory, University of Aarhus, Denmark.
authors.forename: E S
authors.initials: ES
authors.lastname: Sørensen
authors.forename: L K
authors.initials: LK
authors.lastname: Rasmussen
authors.forename: L
authors.initials: L
authors.lastname: Møller
authors.forename: P H
authors.initials: PH
authors.lastname: Jensen
authors.forename: P
authors.initials: P
authors.lastname: Højrup
authors.forename: T E
authors.initials: TE
authors.lastname: Petersen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002417:Cattle; D005973:Glutamine / Q000737:chemistry*; D008969:Molecular Sequence Data; D053495:Osteopontin; D012795:Sialoglycoproteins / Q000737:chemistry*; D013057:Spectrum Analysis; D011503:Transglutaminases / Q000737:chemistry*
chemical_list: D012795:Sialoglycoproteins; D005973:Glutamine; D053495:Osteopontin; D011503:Transglutaminases