Partial purification of the aminopeptidase from the midgut of the human body louse, Pediculus humanus humanus

The midgut of the human body louse Pediculus humanus humanus contains a the rmally stable leucine aminopeptidase, which was detected by agarose gel ele ctrophoresis using L-amino oxidase. Midgut extracts were homogenized in sal ine or in 1% Triton X-100 and the aminopeptidase was purified by Superose 6 gel filtration chromatography. A peak with enzyme activity that was extrac ted with or without Triton X-100 was eluted at a molecular weight 67-69 kDa . Non-denaturing polyacrylamide gel electrophoresis resolved one band of mo lecular weight of 69 kDa for samples that were extracted in a saline buffer . Two closely linked bands of molecular weight 67 kDa and 69 kDa were obser ved in samples that were extracted in 1% Triton X-100.