Apolipoprotein L-1 Promotes Trypanosome Lysis By Forming Pores In Lysosomal Membranes

Apolipoprotein L-I is the trypanolytic factor of human serum. Here we show that
this protein contains a membrane pore-forming domain functionally similar to that
of bacterial colicins, flanked by a membrane-addressing domain. In lipid bilayer
membranes, apolipoprotein L-I formed anion channels. In Trypanosoma brucei,
apolipoprotein L-I was targeted to the lysosomal membrane and triggered
depolarization of this membrane, continuous influx of chloride, and subsequent
osmotic swelling of the lysosome until the trypanosome lysed.