Five pepsinogens were identified in lizard fish (Saurida wanieso) stomach and two of them (PG-I and PG-II) were purified to homogeneity by column chromatographies on DEAE-Sephacel, Ultrogel AcA54, DEAE-Sepharose and Poly-L-Lysine Agarose. The molecular weights of the two purified PGs were about 41 kDa. Both pepsinogens were converted into pepsins within a few minutes under pH 2.5. Corresponding pepsins were also purified by a chromatography on S-Sepharose and their molecular weights were 36 kDa as determined on SDS-PAGE. Optimum pHs of the pepsins were around 3.5 and optimum temperatures were 45? using hemoglobin as substrate. Both enzymes showed high sensitivity toward pepstatin A, a specific inhibitor of aspartic proteinases. The N-terminal amino acid sequences of PG-I and PG-II as determined to the 16th residue were exactly the same and showed high identity to pepsinogens of other animals.
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