Abstract
An aminopeptidase has been purified from membrane ghosts of mouse erythrocyte infected with Plasmodium berghei (NK-65 strain) by a simple method involving selective extraction with 1.0% Triton X-100, and chromatography on Sephadex G-100 and DEAE-Sephadex A-25. An enzyme activity is assayable conveniently with Ala-pNA or Leu-pNA as substrate at 405 nm.
1. This enzyme has a molecular weight of 100, 000 as measured by gel filtration on Sephadex G-100.
2. The enzyme is inhibited by bestatin and chymostatin, and slightly inhibited by E64 but not by pepstatin A, leupeptin and antipain.
3. The enzyme has an essential sulfhydryl group at the active site which is rapidly modified by Hg2+, and slowly by PCMB, but is unaffected by monoiodoacetic acid and N-ethyl-maleimide.
