Limited proteolysis of liver and muscle aldolases: Effects of subtilisin,cathepsin B,and Staphylococcus aureus protease

Limited proteolysis of rabbit liver and muscle aldolases by subtilisin and cathepsin B results in decreased catalytic activity, associated with the release of acid-soluble peptides from the COOH terminus. Analysis of the sequence of these peptides confirms the COOH-terminal sequence of the muscle enzyme and provides new information on the COOH-terminal sequence of the liver enzyme. As previously reported for muscle aldolase, cathepsin B releases mainly dipeptides from the COOH terminus of liver aldolase. The COOH-terminal sequence of rabbit liver aldolase is SerThrGlnSerLeuPheThrAla SerTyrThrTyr. The Gln-Ser bond is resistant to Staphylococcus aureus protease, which hydrolyzes a GluSer bond at the corresponding positions in the muscle enzyme.