| Trichomonas vaginalis is the cause of human trichomoniasis. Although acquisition of iron by binding to host hemoglobin through distinct receptor(s) has been described in this parasite, no specific hemoglobin-binding site has been reported.;The in vitro hemolytic activities of four T. vaginalis strains were examined. No correlation between hemolytic activity and virulence in different isolates was found.;Using hemoglobin-affinity chromatography, two protein bands of approximately 48 and 63 kDa were detected, the former binds preferentially to heme. Mass spectral analysis indicated that the 48- and 63-kDa proteins had significant homology with the subunits of two T. vaginalis adhesins: AP51 and AP65, respectively.;This study confirms the existence of multifunctional proteins in T. vaginalis, which enable the parasite to survive in a constantly changing environment like human vagina.;Our hypotheses were: (1) hemolytic activity of T. vaginalis isolates correlates with the virulence, and (2) T. vaginalis binds hemoglobin through a specific surface receptor. |
