MOLECULAR-CLONING AND SEQUENCE-ANALYSIS OF THE AGGRECAN INTERGLOBULARDOMAIN FROM PORCINE, EQUINE, BOVINE AND OVINE CARTILAGE - COMPARISON OF PROTEINASE-SUSCEPTIBLE REGIONS AND SITES OF KERATAN SULFATE SUBSTITUTION

Oligonucleotide primers which were designed based on identical peptide sequences flanking the interglobular domain (IGD) of human, bovine an d rat aggrecan were used in RT-PCR reactions containing human, porcine , equine, bovine and ovine cartilage RNA. Novel cDNAs encoding the IGD of the latter four species were obtained and sequenced. The deduced a mino acid sequences for these cDNAs were aligned and compared with tho se described for six other species. Amino acid sequences surrounding t he major proteolytic cleavage sites in the IGD are highly conserved, w ith some species-specific substitutions. Similarly, known sites of ker atan sulfate attachment in the IGD are highly conserved in all species . The results provide essential amino acid sequence data for species c ommonly used in model systems of cartilage degeneration.