Partial characterization and post-feeding activity of midgut aminopeptidase in the human body louse, Pediculus humanus humanus

A leucine aminopeptidase was found in the midgut of the human body louse, P ediculus humanus humanus L. (Anoplura: Pediculidae). The enzyme is activate d by the bloodmeal with a pH optimum at 8. The enzyme is soluble in both. a queous and detergent-containing solutions. The two forms of the enzyme had the same Km but exhibited different catalytic activities with regard to Vma x values in these solutions. The enzyme is inhibited competitively by a sub strate analogue 1,10-phenanthroline and by Mn2+ ions in the presence and ab sence of detergent.