C-13 Labelling and electrospray mass spectrometry reveal a de novo route for inositol biosynthesis in Leishmania donovani parasite

摘要

In this paper we provide evidence for the presence of a de novo route for myo-inositol biosynthesis in the protozoan parasite Leishmania donovani, by the application of C-13 labelling and electrospray ionisation mass spectrometry (ESMS). For this myo-[1-C-13]inositol is prepared from D-[6-C-13]glucose and biosynthetically incorporated in the parasite promastigote cell culture. Biosynthetic phosphatidylinositol (PI) and its hydrolysis products glycero-PI and inositol are analysed by ESMS and the isotopomeric ratio determined. The incorporation experiments show substantial isotopic dilution, indicating the presence of myo-inositol 1-phosphate synthase (MIP synthase) enzyme in the parasite; this is further confirmed by incorporation of D-[6-C-13]glucose in the parasite phosphatidylinositol. [References: 37]