Accessibility of Trypanosoma brucei procyclic glycosomal enzymes to labeling agents of various sizes and charges

[摘要]

The high efficiency of glycolysis in Trypanosoma brucei has been attributed to impermeability of the glycosomal membrane to most metabolites. However, the strong stimulation of the glycolytic rate by exogenous metabolites and coenzymes in intact glycosomes is only compatible with their accessibility to the internal space. The accessibility of glycosomal enzymes to protein labeling agents of varying charge and size has been investigated. The results show that the glycosomal membrane is permeable to small molecules of the size of metabolites, but impermeable to larger molecules.

[学科分类] 生物化学/生物物理

[关键词] Glycosomal membrane;Latency;Protein labeling;(Trypanosoma brucei);SDS-PAGE;polyacrylamide gel electrophoresis with SDS;DHAP;dihydroxyacetone phosphate;GP;α-glycerophosphate;3-PGA;3-phosphoglycerate;PMSF;phenylmethylsulfonyl fluoride;PEP;phosphoeno/pyruvate;F-6-P;fructose 6-phosphate;[1-14C]EAI;ethyl[1-14C]acetimidate;[1-14C]IAI;isethionyl[1-14C]acetimidate