TY - JOUR
T1 - The carboxypropeptide trimer of type II collagen is a prominent component of immature cartilages and intervertebral-disc tissue
AU - Niyibizi, Christopher
AU - Wu, Jiann Jiu
AU - Eyre, David R.
N1 - Funding Information:
We sincerely thank Dr. Kenneth A. Walsh and members of his laboratory in the Biochemistry Department of the University of Washington for performing the amino-acid sequence analysis, and Ms. Virginia Apone for typing the manuscript. The study was supported by grants from the National Institutes of Health (AR36794 and AR37318).
PY - 1987/12/18
Y1 - 1987/12/18
N2 - Immature bovine cartilages and intervertebral-disc tissue all revealed a prominent protein, not present in the adult tissues, in non-denaturing extracts made with chondroitin ABC lyase (Ec 4.2.2.4), Streptomyces hyaluronidase (EC 4.2.2.1) or 1 M NaCl. The protein ran on SDS-polyacrylamide electrophoresis, before disulphide reduction, as a close doublet of bands of apparent molecular weight 110 000 and 105 000. After reduction, they dissociated respectively into two protein bands at 37 000 and 35 000, indicating that the initial molecules were disulphide-bounded trimers. Amino-terminal sequence analysis established the identity of both proteins (Mr 110 000 and Mr 105 000) as forms of the carboxypropeptide of type II collagen. The larger molecule appeared to be the trimer of intact α1(II) carboxypropeptides and the smaller, a version composed of chains that were ten residues shorter at their amino-terminal ends. The material appears to be identical to chondrocalcin, a protein previously found to be enriched in fetal growth plate and named on the basis that it may play a role in cartilage calcification. The present findings, however, indicate that the protein is equally abundant in all type II collagen-synthesizing young cartilages, including nucleus pulposus of the intervertebral disc and other cartilages that never calcify.
AB - Immature bovine cartilages and intervertebral-disc tissue all revealed a prominent protein, not present in the adult tissues, in non-denaturing extracts made with chondroitin ABC lyase (Ec 4.2.2.4), Streptomyces hyaluronidase (EC 4.2.2.1) or 1 M NaCl. The protein ran on SDS-polyacrylamide electrophoresis, before disulphide reduction, as a close doublet of bands of apparent molecular weight 110 000 and 105 000. After reduction, they dissociated respectively into two protein bands at 37 000 and 35 000, indicating that the initial molecules were disulphide-bounded trimers. Amino-terminal sequence analysis established the identity of both proteins (Mr 110 000 and Mr 105 000) as forms of the carboxypropeptide of type II collagen. The larger molecule appeared to be the trimer of intact α1(II) carboxypropeptides and the smaller, a version composed of chains that were ten residues shorter at their amino-terminal ends. The material appears to be identical to chondrocalcin, a protein previously found to be enriched in fetal growth plate and named on the basis that it may play a role in cartilage calcification. The present findings, however, indicate that the protein is equally abundant in all type II collagen-synthesizing young cartilages, including nucleus pulposus of the intervertebral disc and other cartilages that never calcify.
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U2 - 10.1016/0167-4838(87)90196-8
DO - 10.1016/0167-4838(87)90196-8
M3 - Article
C2 - 3689806
AN - SCOPUS:0023659148
SN - 0167-4838
VL - 916
SP - 493
EP - 499
JO - Biochimica et Biophysica Acta (BBA)/Protein Structure and Molecular
JF - Biochimica et Biophysica Acta (BBA)/Protein Structure and Molecular
IS - 3
ER -