title: Distribution of SIBLING proteins in the organic and inorganic phases of rat dentin and bone.
abstract: The SIBLING protein family is a group of non-collagenous proteins (NCPs) that includes dentin sialophosphoprotein (DSPP), dentin matrix protein 1 (DMP1), bone sialoprotein (BSP), and osteopontin (OPN). In the present study, we compared these four proteins in different phases of rat dentin and bone. First, we extracted NCPs in the unmineralized matrices and cellular compartments using guanidium-HCl (G1). Second, we extracted NCPs closely associated with hydroxyapatite using an EDTA solution (E). Last, we extracted the remaining NCPs again with guanidium-HCl (G2). Each fraction of Q-Sepharose ion-exchange chromatography was analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Stains-All stain, and with western immunoblotting. In dentin, the NH(2)-terminal fragment of DSPP and its proteoglycan form were primarily present in the G1 extract, whereas the COOH-terminal fragment of DSPP was present exclusively in the E extract. The processed NH(2)-terminal fragment of DMP1 was present in G1 and E extracts, whereas the COOH-terminal fragment of DMP1 existed mainly in the E extract. Bone sialoprotein was present in all three extracts of dentin and bone, whereas OPN was present only in the G1 and E extracts of bone. The difference in the distribution of the SIBLING proteins between organic and inorganic phases supports the belief that these molecular species play different roles in dentinogenesis and osteogenesis.
authors: Department of Biomedical Sciences, Baylor College of Dentistry, Texas A & M University System Health Science Center, Dallas, TX 75246, USA.
authors: Bingzhen
authors: B
authors: Huang
authors: Yao
authors: Y
authors: Sun
authors: Izabela
authors: I
authors: Maciejewska
authors: Disheng
authors: D
authors: Qin
authors: Tao
authors: T
authors: Peng
authors: Bradley
authors: B
authors: McIntyre
authors: James
authors: J
authors: Wygant
authors: William T
authors: WT
authors: Butler
authors: Chunlin
authors: C
authors: Qin
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001842:Bone and Bones / Q000737:chemistry*; D002852:Chromatography, Ion Exchange; D003804:Dentin / Q000737:chemistry*; D003810:Dentinogenesis / Q000502:physiology; D004591:Electrophoresis, Polyacrylamide Gel; D016326:Extracellular Matrix Proteins / Q000032:analysis*; D006023:Glycoproteins / Q000032:analysis*; D058574:Integrin-Binding Sialoprotein; D010012:Osteogenesis / Q000502:physiology; D053495:Osteopontin / Q000032:analysis; D010750:Phosphoproteins / Q000032:analysis; D011498:Protein Precursors / Q000032:analysis; D051381:Rats; D012795:Sialoglycoproteins / Q000032:analysis; D000099311:Dentin Sialophosphoprotein
chemical_list: D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D058574:Integrin-Binding Sialoprotein; D053495:Osteopontin; D010750:Phosphoproteins; D011498:Protein Precursors; D012795:Sialoglycoproteins; D000099311:Dentin Sialophosphoprotein; C081635:Dmp1 protein, rat; C546873:Ibsp protein, rat