title: Identification of small collagenous proteins with properties of procollagen alpha 1 (I) pN-propeptide in fetal porcine calvarial bone.
abstract: Several small collagenous apatite binding (SCAB) proteins have been extracted from the mineralized matrix of fetal porcine calvarial bone. One protein (SCAB 3), released on demineralization of bone with 0.5 M EDTA, appears to represent the alpha 1 pN-propeptide that is normally released during proteolytic processing of type I procollagen. The 28 Kd protein, which stains blue with "Stains-all", is reduced to a 19 Kd fragment by bacterial collagenase digestion, but is not susceptible to cyanogen bromide. The amino acid composition, blocked amino-terminus and immunological properties are all consistent with properties of alpha 1 (I) pN-propeptide. Fractionation on hydroxylapatite in the presence of urea has revealed a nonbinding (SCAB 3a) and a binding (SCAB 3b) form. Extraction of the demineralized matrix of bone with 4 M GuHCl revealed a third form (G2-28) which was similar to SCAB 3a on hydroxylapatite chromatography but showed differences on FPLC "Mono Q" resin. The occurrence of these different forms of pN-propeptide in bone may be of significance in collagen fibril-associated hydroxylapatite formation and in the regulation of osteoblastic function during bone resorption.
authors.affiliation: Medical Research Council Group in Periodontal Physiology, University of Toronto, Ontario, Canada.
authors.forename: H A
authors.initials: HA
authors.lastname: Goldberg
authors.forename: M
authors.initials: M
authors.lastname: Maeno
authors.forename: C
authors.initials: C
authors.lastname: Domenicucci
authors.forename: Z N
authors.initials: ZN
authors.lastname: Qi
authors.forename: J
authors.initials: J
authors.lastname: Sodek
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001842:Bone and Bones / Q000032:analysis* / Q000196:embryology; D003094:Collagen / Q000032:analysis*; D005326:Fetal Proteins / Q000032:analysis; D011347:Procollagen / Q000032:analysis*; D013552:Swine
chemical_list: D000596:Amino Acids; D005326:Fetal Proteins; D011347:Procollagen; D003094:Collagen