Abstract
The presumed wound-healing phenoloxidase of Calpodes ethlius has been purified from the cuticle of last instar larvae and has been shown to be a typical tyrosinase (EC 1.10.3.1, o-diphenol: O2 oxidoreductase) similar to enzyme A of Calliphora vicina. The enzyme is active toward o-diphenols but not p-diphenols, is readily inhibited by thiourea and phenylthiourea, and has a pH optimum between 6.5 and 7.6. The appearance of enzyme activity in the cuticle is affected by pH in a manner that supports the hypothesis, based on earlier histochemical evidence, that the phenoloxidase arises from a previously inactive proenzyme.