Partial structure of glutamic acid and alanine-rich protein, a major surface glycoprotein of the insect stages of Trypanosoma congolense
Partial structure of glutamic acid and alanine-rich protein, a major surface glycoprotein of the insect stages of Trypanosoma congolense
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DOI：
10.1074/jbc.m208942200
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发表时间：
2002-12-13
影响因子：
4.8
通讯作者：
Ferguson, MAJ
中科院分区：
文献类型：
--
作者：
Thomson, LM;Lamont, DJ;Ferguson, MAJ
舌蝇传播的唾液锥虫，即纳米单胞菌亚属的刚果锥虫，是撒哈拉以南非洲地区家畜病理中最重要的锥虫。与锥虫亚属的相关锥虫布鲁氏锥虫不同，刚果锥虫昆虫阶段的主要表面分子特征很差。本文描述了刚果螺杆菌原环型和附马鞭毛虫型主要表面糖蛋白之一的富含谷氨酸和丙氨酸的蛋白的纯化和结构表征。糖蛋白是糖基磷脂酰肌醇锚定的分子，具有半乳糖基化的糖基磷脂酰肌醇锚定，含有sn-1-硬脂酰-2- l- 3- hpo4 -1-（2- o -酰基）- d -肌醇磷脂片段。21.6 kda的多肽组分携带两个大的含甘露糖和半乳糖的低聚糖，通过磷酸二酯键与苏氨酸残基连接。色氨酸消化的质谱分析表明，几个或所有密切相关的谷氨酸和富丙氨酸蛋白基因在刚果螺旋体群体中同时表达。
The tsetse fly transmitted salivarian trypanosome, Trypanosoma congolense of the subgenus Nanomonas, is the most significant of the trypanosomes with respect to the pathology of livestock in sub-Saharan Africa. Unlike the related trypanosome Trypanosoma brucei of the subgenus Trypanozoon, the major surface molecules of the insect stages of T. congolense are poorly characterized. Here, we describe the purification and structural characterization of the glutamic acid and alanine-rich protein, one of the major surface glycoproteins of T. congolense procyclic and epimastigote forms. The glycoprotein is a glycosylphosphatidylinositol-anchored molecule with a galactosylated glycosylphosphatidylinositol anchor containing an sn-1-stearoyl-2-L-3-HPO4-1-(2-O-acyl)-D-myoinositol phospholipid moiety. The 21.6-kDa polypeptide component carries two large mannose- and galactose-containing oligosaccharides linked to threonine residues via phosphodiester linkages. Mass spectrometric analyses of tryptic digests suggest that several or all of the closely related glutamic acid and alanine-rich protein genes are expressed simultaneously in a T. congolense population growing in vitro.