Purification of progelatinases A and B by continuous-elution electrophoresis

Progelatinases A and B were purified from HT1080-conditioned culture medium using a continuous-elution electrophoresis. Initially cell culture medium was ammonium sulfate precipitated. The concentrated proteins were affinity chromatographed on gelatin-Sepharose column. The bound gelatinases were eluted with electrophoresis sample buffer and subjected to continuous-elution electrophoresis. In a single run, under the standardized working conditions, the obtained fractions contained four purified enzymes--progelatinase A (M(r) 72,000), its activated forms (M(r) 62,000 and M(r) 59,000), and progelatinase B (M(r) 92,000). Moreover, the continuous-elution electrophoresis allowed the enzymes separation from their respective inhibitors--TIMP-1 (M(r) 28,500) and TIMP-2 (M(r) 21,000). The purified progelatinases A and B demonstrated high specific activities (150-200 U/micrograms).