High-Confidence Glycosome Proteome for Procyclic Form Trypanosoma brucei by Epitope-Tag Organelle Enrichment and SILAC Proteomics

The glycosome of the pathogenic African trypanosome Trypanosoma brucei is a specialized peroxisome that contains most of the enzymes of glycolysis and several other metabolic and catabolic pathways. The contents and transporters of this membrane-bounded organelle are of considerable interest as potential drug targets. Here we use epitope tagging, magnetic bead enrichment, and SILAC quantitative proteomics to determine a high-confidence glycosome proteome for the procyclic life cycle stage of the parasite using isotope ratios to discriminate glycosomal from mitochondrial and other contaminating proteins. The data confirm the presence of several previously demonstrated and suggested pathways in the organelle and identify previously unanticipated activities, such as protein phosphatases. The implications of the findings are discussed.

致病非洲锥虫布氏锥虫（Trypanosoma brucei）的糖酵解体（glycosome）是一类特化过氧化物酶体，内含绝大多数糖酵解酶类以及多种其他代谢与分解代谢途径的相关组分。该膜包被细胞器的内部组分与转运蛋白作为潜在药物靶点，具有重要研究价值。本研究采用表位标签技术、磁珠富集法及细胞培养稳定同位素氨基酸标记（SILAC）定量蛋白质组学方法，通过同位素比值区分糖酵解体蛋白与线粒体及其他污染蛋白，从而鉴定出该寄生虫前循环生命周期阶段的高置信度糖酵解体蛋白质组。本研究数据不仅证实了该细胞器中数种此前已被证实及推测的代谢途径的存在，还鉴定出此前未被发现的蛋白活性，例如蛋白磷酸酶。本文对本研究发现的潜在意义进行了讨论。