Properties of an Alkaline Protease From the Skeletal Muscle of Atlantic Croaker

An alkaline protease was partially purified from the skeletal muscle of Atlantic croaker. The protease is a cytoplasmic enzyme and heat stable. The enzyme preparation was shown to degrade fish actomyosin in vitro between 50–60°C. The enzyme is a sulfhydryl protease and does not require Ca++ ions for its activity. Preparations of the enzyme do not hydrolyze TAME, BTEE or denatured hemoglobin. Column chromatographic analyses suggest an apparent molecular weight of 80,000 ± 4,000 and the isoelectric point is 6.0 ± 0.2.