Purification and characterization of chymotrypsin from Penaeus vannamei (Crustacea: Decapoda)

?he purification and characterization of a chymotrypsin from the hepatopancreas of the white shrimp Penaeus vannamei is described. Only one chymotrypsin was detected in contrast to other shrimp that have two major forms. P. vannamei chymotrypsin has a molecular mass of 33.2 kDa and a pi of 3,1. The molecular mass is high relative to other penaeid chymotrypsins, The proteinase is acid labile and exhibits optimum activity at pH 8, The enzyme is thermostable both at 25 and 37C, It is a serine proteinase, Phenylmethylsulphonyl fluoride and soybean trypsin inhibitor blocked the activity of the enzyme, and it was not affected by chymotrypsin inhibitors such as tosyl-PheCH(2)Cl or benzyloxycarbonyl-Phe-CH2Cl. Protein profiles of the hepatopancreas from two populations varied and this is suspected to be caused by differences in the expression of chymotrypsin in the white shrimp.