The Global Architecture of the Mycobacterial Cell Envelope

摘要: The cell envelope of mycobacteria, i.e., the compounds that surround cytoplasm and protect micro-organisms from their environment, is important for bacterial physiology because inhibition production some its constituents, e.g., mycolic acids arabinogalactan, kills cells. It also this structure controls transfer materials into out mycobacterium. wall possesses a fundamental, covalently linked “cell-wall skeleton” (CWS) associated with great variety noncovalently substances, which majority are lipids glycolipids. Isolated plasma membranes typically obtained by breaking cells mechanical stress, sonication or shearing in French pressure cell, followed fractionation using differential centrifugation density gradients. mycobacteria consists CWS, an abundant wall-associated few polypeptides. That outermost layer mycobacterial partly polysaccharide nature could be deduced staining electron-transparent zone (ETZ) peroxidase-conjugated concanavalin A old data showing culture filtrates, notably preparation called tuberculin, contain several polysaccharides. polysaccharide/protein matrix pathogens would serve as defense mechanism facilitating survival host. capsule constituents can act actively modifying behavior host way beneficial to bacterium, recently shown glucan Mycobacterium tuberculosis.