Compound discovery and expression of a putative cathepsin D-like protease in Trichomonas vaginalis.

摘要

Trichomonas vaginalis is a sexually-transmitted parasite that is the causative agent in the disease trichomoniasis. Resistance to the only FDA-approved medication to this disease, metronidazole, has been on the increase giving rise to the need for finding targets for new inhibitors to exploit. New inhibitors can target enzymes such as 4-coumarate:CoA ligase and S-adenosylhomocysteine hydrolase. Another potential target is a cathepsin D-like protease found in T. vaginalis. This aspartic protease in humans is responsible for degrading proteins in the lysosome, and degrading hemoglobin in P. falciparum as the homologue plasmepsin. Searching the gene database, only one cathepsin-D like protease was discovered throughout the organism's genome. Utilizing RT-PCR, this gene is found to be expressed in two different strains of the organism. Transfection of an epitope-tagged version of this cathepsin D-like protease into T. vaginalis was accomplished, and subsequent immunofluorescence of this tagged version shows it to be localized in intracellular compartments, which can be colocalized using the SNARE and VAMP proteins found in T. vaginalis .