PURIFICATION AND CHARACTERIZATION OF A TRYPSIN-LIKE-ENZYME FROM THE HEPATOPANCREAS OF CRAYFISH (PROCAMBARUS-CLARKII)

1. A trypsin-like enzyme was purified from the hepatopancreas of Louisiana swamp crayfish, Procambarus clarkii, by a combination of hydrophobic interaction chromatography, molecular sieving and ion-exchange chromatography. 2. The enzyme had a molecular weight of 33.6 kDa on SDS-PAGE and an isoelectric point of 3.0. 3. The enzyme exhibited optimal activity at pH 8.0 and an optimal temperature of 55-degrees-C. It was stable in the pH range of 7.5-9.0, but unstable above 55-degrees-C. 4. The tryptic activity was inhibited by phenylmethyl sulfonyl fluoride and other well-established trypsin inhibitors. 5. Immunological study showed that crayfish trypsin-like enzyme shared structural components with bovine trypsin.