Cleavage of cartilage proteoglycan between G1 and G2 domains by stromelysins

• Published in: The Journal of biological chemistry Vol. 266; no. 24; pp. 15579 - 15582
• Main Authors: FOSANG, A. J, NEAME, P. J, HARDINGHAM, T. E, MURPHY, G, HAMILTON, J. A
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Biochemistry and Molecular Biology 25.08.1991
• Subjects: Amino Acid Sequence; Analytical, structural and metabolic biochemistry; Animals; Autoradiography; Biological and medical sciences; Cartilage - chemistry; Cartilage - metabolism; Electrophoresis, Polyacrylamide Gel; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Humans; Hydrolases; Hydrolysis; Matrix Metalloproteinase 10; Matrix Metalloproteinase 3; Metalloendopeptidases - metabolism; Molecular Sequence Data; Proteoglycans - genetics; Proteoglycans - metabolism; Recombinant Proteins - metabolism; Swine; Proteoglycan; Vertebrata; Mammalia; Articular cartilage; Domain structure; Enzyme; Cleavage site; Enzymatic digestion; Metalloproteinase; Artiodactyla; Ungulata; Pig
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)98442-5

Normal and pathological turnover of proteoglycans in articular cartilage involves its cleavage close to the N-terminal G1 domain responsible for aggregation. A fragment containing G1 and G2 N-terminal domains of pig cartilage proteoglycans was therefore used as a substrate to investigate its degradation by the metalloproteinase stromelysin and related recombinant stromelysin enzymes. The stromelysins produced an apparent single cleavage yielding a G1 fragment of 56 kDa and a G2 fragment of 110 kDa. Rabbit bone stromelysin was much more active against the G1-G2 fragment and against proteoglycan aggregates than recombinant human stromelysin-1 and stromelysin-2. All metalloproteinase preparations were active against proteoglycan and the G1-G2 fragment at acid (pH 5.5) and neutral pH (7.4). N-terminal sequencing of the G2 fragment derived from the action of recombinant human stromelysin-1 revealed that cleavage between G1 and G2 occurred at the N-terminal end of the interglobular domain, close to the last cysteine in G1. The specific cleavage site was between an asparagine and a pair of phenylalanine residues, where the asparagine corresponds to residue 341 in human and rat mature core protein sequence.