PURIFICATION OF SN-GLYCEROL-3-PHOSPHATE DEHYDROGENASE FROM TRYPANOSOMA-BRUCEI-BRUCEI

A protein has been purified from the membranes of bloodstream forms of Trypanosoma brucei brucei. The purified material contained a single p olypeptide chain of molecular mass 67 kilodaltons as judged by sodium dodecyl sulfate - polyacrylamide gel electrophoresis; under "native" c onditions it migrated through a Sephacryl S-300 column with a similar molecular mass. The purified protein catalysed electron transfer from sn-glycerol 3-phosphate to oxygen with the subsequent formation of wat er. Electron transfer by the purified enzyme to O2 was dependent on th e presence of low concentrations of the mediator phenazine methosulfat e. This protein is clearly the major membrane-bound sn-glycerol-3-phos phate dehydrogenase, but it also has some characteristics suggestive o f the trypanosome alternative oxidase activities.