Characterization of mineral-binding 40-kDa glycoprotein extracted from young adult rabbit alveolar bone.
A forty-kilodalton (40-kDa) protein was extracted from alveolar bone of young adult rabbit with 0.5 M EDTA after extraction with 4 M GuHCl, and purified by gel-filtration, anion-exchange and hydroxyapatite columns using a high-pressure liquid chromatography system under denaturing conditions. The purified 40-kDa protein was not susceptible to bacterial collagenase and thrombin, but was cleaved by cyanogen bromide. The protein was stained blue with Stains-all. Among various lectins, concanavalin A and lentil lectin agglutinin bound to this protein, but peanut agglutinin, Ricinus communis agglutinin, phytohemagglutinin-E and wheatgerm lectin agglutinin did not. Lectin binding assays showed that the protein is a glycoprotein containing large amounts of mannose and/or glucose residues, but is not a fragment of proteoglycan. The amino acid composition of the protein shows a characteristically high content of acidic amino acids. Therefore, the mineral-binding 40-kDa glycoprotein is considered to be osteonectin/secreted protein acidic and rich in cysteine (SPARC), in terms of similarities to bovine and porcine osteonectins with regard to molecular weight and contents of glycoses and amino acids.
Maeno
M
M
Department of Biochemistry, Nihon University School of Dentistry, Tokyo, Japan.
Taguchi
M
M
Suzuki
N
N
Ogoshi
T
T
Naganuma
K
K
Tamura
Y
Y
Nakano
K
K
Komori
F
F
Otsuka
K
K
Suzuki
K
K
D000539:Alveolar Process / Q000737:chemistry*; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D015153:Blotting, Western; D002847:Chromatography, Agarose; D002851:Chromatography, High Pressure Liquid; D003488:Cyanogen Bromide; D004591:Electrophoresis, Polyacrylamide Gel; D008334:Mandible / Q000737:chemistry; D003012:Microbial Collagenase; D008903:Minerals / Q000737:chemistry; D008970:Molecular Weight; D015676:Osteonectin / Q000737:chemistry / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D011817:Rabbits; D012685:Sepharose; D012834:Silver; D012967:Sodium Dodecyl Sulfate
D000596:Amino Acids; D008903:Minerals; D015676:Osteonectin; D012967:Sodium Dodecyl Sulfate; D012834:Silver; D012685:Sepharose; D003012:Microbial Collagenase; D003488:Cyanogen Bromide