Evidence for the involvement of a tsetse midgut lectin-trypsin complex in differentiation of bloodstream-form trypanosomes
Abstract
We have previously described a bloodmeal-induced molecule (lectin-trypsin complex) from the midgut of the tsetse fly, Glossina longipennis, with both lectin and trypsin activities (Osir et al., 1995). In this paper, we report on the isolation of a similar molecule from the midguts of Glossina fuscipes fnscipes and provide direct evidence for its involvement in the development of African trypanosomes. The molecule (native Mr 65,700) has two non-covalently linked subunits, Mr 28,800 and Mr 35,700. The native molecule was found to be capable of inducing differentiation of bloodstream-form trypanosomes into procyclic (midgut forms) in vitro. In the assays, specific antibodies against procyclin were used to monitor the transformation of the bloodstream-form trypanosomes into procyclic forms. This induction was specifically inhibited by D-glucosamine. Cis-aconitate was also capable of inducing the transformation process with the same efficiency as that of the lectin-trypsin complex. While increasing the concentrations of the lectin-trypsin complex (≥100 μg protein/ml) in the incubation assays resulted into higher transformation rates, it also led to high parasite mortality. These results provide evidence for the involvement of the midgut lectin-trypsin complex in the differentiation of bloodstream-form trypanosomes within tsetse midgut.
Citation
J, PROFMULAAFRANCIS. 2003. Evidence for the involvement of a tsetse midgut lectin-trypsin complex in differentiation of bloodstream-form trypanosomes. Insect Sci. Applic. 23(3). 197. Bull Entomol Res. 2003 Feb;93(1):1-10. : SpringerlinkPublisher
University of Nairobi College of biological and physical science