Identification of proteins in the exosporium of Bacillus anthracis
Identification of proteins in the exosporium of Bacillus anthracis
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DOI：
10.1099/mic.0.26681-0
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发表时间：
2004-02-01
期刊：
影响因子：
2.8
通讯作者：
Moir, A
中科院分区：
文献类型：
--
作者：
Redmond, C;Baillie, LWJ;Moir, A
炭疽杆菌的孢子是炭疽病的病原体，具有外孢壁。作为这些成熟孢子的外表面层，孢子外壁代表孢子与环境/宿主之间的主要接触表面，并且是孢子抗原的位点。从B的内生孢子中分离出外孢壁。炭疽菌野生型艾姆斯菌株，来自质粒pXO 2（-）治愈的艾姆斯菌株的衍生物，以及来自先前分离的pXO 1（-）、pXO 2（-）双重治愈菌株，B。炭疽菌UM 23 Cl 2。SDS-PAGE分离的外孢壁提取物的蛋白质图谱对于所有三种都是相似的。这表明，缺乏一个或两个质粒的无毒变体是研究B孢子外孢壁的现实模型。炭疽病从通过纳米喷雾-MS/MS或N-末端测序确定的氨基酸序列中鉴定了许多松散吸附的蛋白质。盐和洗涤剂洗涤的外孢壁片段除去这些和揭示的蛋白质，可能代表结构/完整的外孢壁蛋白。在洗净的外孢壁中鉴定出7种蛋白质：丙氨酸消旋酶、肌苷水解酶、ExsF、CotY、ExsY、CotB和一种新的蛋白质ExsK。CotY、ExsY和CotB是枯草芽孢杆菌外孢子外壳蛋白的同源物，但ExsF和ExsK对B具有特异性。炭疽菌和蜡状芽孢杆菌组的其他成员。
Spores of Bacillus anthracis, the causative agent of anthrax, possess an exosporium. As the outer surface layer of these mature spores, the exosporium represents the primary contact surface between the spore and environment/host and is a site of spore antigens. The exosporium was isolated from the endospores of the B. anthracis wild-type Ames strain, from a derivative of the Ames strain cured of plasmid pXO2(-), and from a previously isolated pXO1(-), pXO2(-) doubly cured strain, B. anthracis UM23Cl2. The protein profiles of SDS-PAGE-separated exosporium extracts were similar for all three. This suggests that avirulent variants lacking either or both plasmids are realistic models for studying the exosporium from spores of B. anthracis. A number of loosely adsorbed proteins were identified from amino acid sequences determined by either nanospray-MS/MS or N-terminal sequencing. Salt and detergent washing of the exosporium fragments removed these and revealed proteins that are likely to represent structural/integral exosporium proteins. Seven proteins were identified in washed exosporium: alanine racemase, inosine hydrolase, ExsF, CotY, ExsY, CotB and a novel protein, named ExsK. CotY, ExsY and CotB are homologues of Bacillus subtilis outer spore coat proteins, but ExsF and ExsK are specific to B. anthracis and other members of the Bacillus cereus group.