Cartilage-degrading neutral proteinase secreted by Yoshida sarcoma cells. Purification and properties

The Yoshida sarcoma, a malignant rat tumor, has been reported by Machinami ( Machinami , R. (1972) Acta Pathol. JPN 22, 19-39) to destroy cartilage matrix in vivo. We have characterized an enzyme secreted by Yoshida sarcoma cells in culture which degrades cartilage proteoglycan in solution and also in situ in organ culture ( Mikuni - Takagaki , Y., and Gross, J. (1981) in Proceedings of the 6th International Symposium on Glycoconjugates ( Yamakawa , T., Osawa , T., Handa , S., eds) pp. 491-492, Japan Scientific Societies Press, Tokyo) ( Mikuni - Takagaki , Y., and Gross, J. (1982) in The Extracellular Matrix ( Hawkes , S., and Wang, J.L., eds) pp. 379-385, Academic Press, New York). In this report we characterized the isolated enzyme with the help of a new assay system for measurement of proteoglycan core protein degradation, which utilizes aminopropyl glass beads derivatized with hyaluronic acid. This enzyme, with a neutral pH optimum and apparent molecular weight of about 30,000, is secreted into culture medium in an active form. It is resistant to cartilage-derived inhibitors and to alpha 2-macroglobulin as well as to synthetic and natural inhibitors of serine-, thiol- and carboxylproteinases . It is inhibited by a chelating agent, 1,10-phenanthroline and thiol compounds at relatively high concentrations, and therefore is probably a metalloproteinase. The enzyme degrades type V collagen, types I and II denatured collagen (gelatin), and casein in addition to cartilage proteoglycan, but not bovine serum albumin, myoglobin, fibrinogen, elastin or native collagen types I, II, III, and IV. These findings suggest that the Yoshida sarcoma may degrade cartilage matrix in vivo by means of a secreted, active, inhibitor-resistant enzyme.