Chemical and ultrastructural investigations of Mycobacterium bovis BCG: Implications for the molecular structure of the mycobacterial cell envelope
Chemical and ultrastructural investigations of Mycobacterium bovis BCG: Implications for the molecular structure of the mycobacterial cell envelope
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DOI：
10.1111/j.1574-695x.1996.tb00087.x
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发表时间：
1996-10-01
影响因子：
--
通讯作者：
Groves, MJ
中科院分区：
文献类型：
--
作者：
Klegerman, ME;Devadoss, PO;Groves, MJ
通过透射电子显微镜（TEM）观察树脂包埋标本的薄片，分枝杆菌细胞壁通常被认为由电子致密的肽聚糖、电子透明的阿拉伯半乳糖酸层和电子致密的外层（OL）组成。此外，在巨噬细胞吞噬分枝杆菌后，还观察到称为“电子透明区”（ETZ）的假胶囊。牛分枝杆菌BCG， Tice(R)亚株的透射电镜切片显示OL双分子层，每个双分子层直径为2-4 nm。中间电子透明层的直径从1纳米到约250纳米不等，似乎是以前观察到的依赖氧的无定形被膜，由热水可提取的中性多糖组成，特别是最近表征的a-葡聚糖，约占干细胞重量的12%。这项研究和最近其他关于卡介苗的研究揭示了细胞表面特征，这可能有助于更好地了解分枝杆菌外包膜。
The mycobacterial cell wall visualized by transmission electron microscopy (TEM) of thin sections of resin-embedded specimens is generally believed to consist of an electron-dense peptidoglycan, an electron-transparent arabinogalactanmycolate layer and an electron-dense outer layer (OL). In addition, a pseudocapsule known as the 'electron-transparent zone' (ETZ) has been observed after phagocytosis of mycobacteria by macrophages. TEM of thin sections of Mycobacterium bovis BCG, Tice(R) substrain, revealed an OL bilayer, each of which measured 2-4 nm in diameter. The intermediate electron-transparent layer varied from 1 to about 250 nm in diameter and appears to be a previously observed oxygen-dependent amorphous integument that consists of hot water-extractable neutral polysaccharides, especially a recently characterized a-glucan, comprising about 12% of the dry cell weight. This and other recent studies of BCG have revealed cell-surface features that may provide a better understanding of the outer mycobacterial cell envelope.