Schistosoma japonicum: ultrastructural localization of a hemoglobinase using mercury labeled pepstatin

Mercury labeled pepstatin was used to demonstrate the site of a pepstatin sensitive hemoglobinase in paraformaldehyde fixed adult Schistosoma japonicum. Pepstatin was covalently attached to glutathione using dicyclohexylcarbodiimide followed by addition to methyl mercury chloride. Deposition of mercury was observed in lipid-like globules and autophagic vacuoles in the gastrodermis. Control studies were negative in all instances. These results complement previous cytochemical studies on the distribution of other acid hydrolases in the gastrodermis of schistosomes. It is hypothesized that this pepstatin sensitive enzyme probably belongs to the carboxyl class of proteinases.