SOME ENZYMIC PROPERTIES OF A PARTIALLY PURIFIED AMINOACYLASE OBTAINED FROM A POLISH VARIETY OF RAPESEED (BRASSICA CAMPESTRIS L.)

Abstract

Aminoacylase, which hydrolyzes N-acetyl amino acids, has been demonstrated in rapeseed. The enzyme was purified 150-fold by fractionation with ammonium sulphate and calcium phosphate gel. The purified preparation hydrolyzed N-acetyl amino acids and in addition certain dipeptides and chloracetyl-L-tyrosine. The enzyme was stable at −20 °C and had a wide pH optimum (7.2 to 8.8). Cobalt ion was found to be an activator, while sulphydryl-reacting agents such as p-chloromercuribenzoate and some metal-chelating agents inhibited the hydrolysis. The enzyme showed rigorous specificity for the L-isomer. A comparison of the ratio of activities obtained for different enzyme preparations indicates that more than one enzyme is concerned in the hydrolysis of the different substrates.