KINETOPLASTID MEMBRANE PROTEIN-11 (KMP-11) IS DIFFERENTIALLY EXPRESSED DURING THE LIFE-CYCLE OF AFRICAN TRYPANOSOMES AND IS FOUND IN A WIDEVARIETY OF KINETOPLASTID PARASITES

An abundant 11-kDa membrane protein was purified from African trypanos omes by organic solvent extraction and octyl-Sepharose chromatography. This protein cross-reacts with monoclonal antibodies originally gener ated against the lipophosphoglycan-associated protein of Leishmania do novani. Immunoblot analysis showed that the 11-kDa molecule was presen t in a variety of species of kinetoplastids. It was found in several s pecies and subspecies of African trypanosomes and was present in low a mounts in bloodstream forms and in larger amounts in procyclic, epimas tigote and metacyclic life cycle stages. Expression of the 11-kDa mole cule rapidly increased during transformation from bloodstream forms to procyclic forms, paralleling expression of the major surface glycopro tein of Trypanosoma congolense, the glutamic acid/alanine-rich protein , an analogue of T. brucei procyclin. The molecule was present in proc yclic trypanosome membranes at approximately 2 X 10(5)-1 X 10(6) molec ules per cell, suggesting it may have an important role in parasite me mbrane organization and function. Amino-acid analysis of the trypanoso me 11-kDa protein showed it had a different composition than that of i ts leishmania counterpart. Its wide distribution in kinetoplastids and its membrane disposition suggest a name for this class of molecules: kinetoplastid membrane protein-11 (KMP-11).