African sleeping sickness is a vector-borne devastating disease caused by the parasitic protozoan Trypanosoma brucei. Of great importance is the fact that, as opposed to other parasitic organisms, trypanosomes synthesize phospholipids de novo. This makes the trypanosome phospholipids biosynthesis machinery a very attractive target for new drug design. We recently identified TbLpn, a protein homologous to yeast and human lipin, a phosphatidate phosphatase involved in membrane biogenesis, energy metabolism, and adipose tissue development. In yeast and mammals, lipin catalyzes the dephosphorylation of phosphatidic acid (PA) to diacylglycerol (DAG) which, in turn, is used for the synthesis of phospholipids. Careful examination of the predicted amino acid sequence of TbLpn has revealed the presence of two conserved domains characteristic of the lipin family of protein, as well as two aspartic acid residues essential for lipin enzymatic activity. This clearly suggests that TbLpn represents a functional homologue of lipin proteins. The aim of this research is to characterize the in vitro enzymatic activity of T. brucei TbLpn. Recombinant His~TbLpn was expressed in Escherichia coli and purified over a nickel column. This purified protein will be used to test the enzymatic activity of TbLpn. It is expected that the immunopurified TbLpn will result in a concentration-dependent release of phosphate from PA.
|Presenter:||Dominic Munini (Graduate Student)|
|Time:||2:30 pm Session IV|