Occurrence of Proteoyltic and Lectin-Degrading Activities in the Bark of Robinia pseudoacacia

Abstract

Various endo- and exopeptidase activities were examined in an extract of the bark of Robinia pseudoacacia L. The crude extract hydrolysed azocasein, gelatin and benzyloxycarbonyl-Phe-Ala (Z-Phe-Ala) at acidic pH and leucine p-nitroanilide (LPA), alanine p-nitroanilide (APA) and N-benzoyl-arginine ρ-nitroanilide (BAPA) at neutral to weakly alkaline pH. The extract also hydrolysed lectin, which is one of the predominant bark proteins, to smaller polypeptides at acidic pH. The proteolytic activities against azocasein and Z-Phe-Ala remained at relatively high levels during the season when the amount of lectin in the bark decreased rapidly.