| pubmed-article:3058624 | pubmed:abstractText | A high-molecular-weight proteinase in rat ascites hepatoma AH109A cells was purified to apparent homogeneity by conventional chromatographic techniques. The purified proteinase degraded over the broad pH range, 7.0-9.0, not only denatured hemoglobin but also type I and IV collagen in the absence of calcium. Its activity was maximum at pH 8.0, heat-labile and affected by thiol reagents. Serine proteinase inhibitors such as diisopropyl fluorophosphate, soybean trypsin inhibitor, leupeptin, and antipain also partially inhibited its activity. The enzyme was found mainly in the cytosol fraction, and had a molecular weight of 450 kilodaltons (Kd) as determined by gel filtration chromatography and showed a single band on polyacrylamide gel electrophoresis under nondenaturing condition, although it was dissociated into lower-molecular-weight subunits, 25.5-32 Kd in the presence of sodium dodecyl sulfate and 2-mercaptoethanol. These properties suggested that it was a kind of a cytosolic high-molecular-weight proteinase. The collagenolytic activity of this proteinase may play an important role in cancer cell invasion and metastasis. | lld:pubmed |
