1. Hookworm Aspartic Protease, Na-APR-2, Cleaves Human Hemoglobin and Serum Proteins in a Host-Specific Fashion.
- Author
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Williamson, Angela L., Brindley, Paul J., Abbenante, Giovanni, Datu, Bennett J.D., Prociv, Paul, Berry, Colin, Girdwood, Karen, Pritchard, David I., Fairlie, David P., Hotez, Peter J., Zhan, Bin, and Loukas, Alex
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HOOKWORMS , *ASPARTIC proteinases - Abstract
Hookworms are voracious blood-feeders. The cloning and functional expression of an aspartic protease, Na-APR-2, from the human hookworm Necator americanus are described here. Na-APR-2 is more similar to a family of nematode-specific, aspartic proteases than it is to cathepsin D or pepsin, and the term "nemepsins" for members of this family of nematode-specific hydrolases is proposed. Na-apr-2 mRNA was detected in blood-feeding, developmental stages only of N. americanus, and the protease was expressed in the intestinal lumen, amphids, and excretory glands. Recombinant Na-APR-2 cleaved human hemoglobin (Hb) and serum proteins almost twice as efficiently as the orthologous substrates from the nonpermissive dog host. Moreover, only 25% of the Na-APR-2 cleavage sites within human Hb were shared with those generated by the related N. americanus cathepsin D, Na-APR-1. Antiserum against Na-APR-2 inhibited migration of 50% of third-stage N. americanus larvae through skin, which suggests that aspartic proteases might be effective vaccines against human hookworm disease. [ABSTRACT FROM AUTHOR]
- Published
- 2003
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