Purification and immunological properties of cathepsin B in carp Cyprinus carpio

Cathespin B was purified from the crude extract of carp (Cyprinus carpio) hepato pancreas by the method involving ammonium sulfate fractionation and five sequential chromatographies monitored thr activity with Z-Arg-Arg-MCA as a substrate, and the specific activity increased about 11,400 fold with a 2% recovery. Although the homogeneity of thr purified cathepsin B was established on Native-PAGE, it migrated as two bands of 29,000 and 25,000 molecular weights by the single and heavy chains on SDS-PAGE, respectively. The monospecific antibody against the homogeneous cathepsin B was purified by the affinity chromatography on cathespin B-Sepharose 4B, and did not immunologically react with rat cathepsin B, carp cathepsins H and L but only with carp cathepsin B by immunoelectrophoretic blot analysis. As the result of the tissue and liver distributions of cathespin B, the remarkable immunological reactivities in thr extracts of spleen, kidney and hepato-pancreas in carp and those of pacific cod, yellow fin tuna, skip jack tuna and common mackerel in pisces were detected with the anti-carp, hepato-pancreas cathepsin B at molecular weight of nearby 29,000 or 25,000.