Molecular Bacteriology and Immunology Group, Institute of Infection, Immunity & Inflammation, Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD, UK.
Mol Microbiol. 2010 May;76(3):605-15. doi: 10.1111/j.1365-2958.2010.07098.x. Epub 2010 Feb 28.
Fructose-1, 6-bisphosphate aldolases (FBA) are cytoplasmic glycolytic enzymes, which despite lacking identifiable secretion signals, have also been found localized to the surface of several bacteria where they bind host molecules and exhibit non-glycolytic functions. Neisseria meningitidis is an obligate human nasopharyngeal commensal, which has the capacity to cause life-threatening meningitis and septicemia. Recombinant native N. meningitidis FBA was purified and used in a coupled enzymic assay confirming that it has fructose bisphosphate aldolase activity. Cell fractionation experiments showed that meningococcal FBA is localized both to the cytoplasm and the outer membrane. Flow cytometry demonstrated that outer membrane-localized FBA was surface-accessible to FBA-specific antibodies. Mutational analysis and functional complementation was used to identify additional functions of FBA. An FBA-deficient mutant was not affected in its ability to grow in vitro, but showed a significant reduction in adhesion to human brain microvascular endothelial and HEp-2 cells compared to its isogenic parent and its complemented derivative. In summary, FBA is a highly conserved, surface exposed protein that is required for optimal adhesion of meningococci to human cells.
果糖-1,6-二磷酸醛缩酶（FBA）是细胞质糖酵解酶，尽管缺乏可识别的分泌信号，但也已在几种细菌的表面定位，在那里它们结合宿主分子并表现出非糖酵解功能。脑膜炎奈瑟菌是一种专性人类鼻咽共生菌，具有引起危及生命的脑膜炎和败血症的能力。重组天然脑膜炎奈瑟菌 FBA 被纯化并用于偶联酶测定，证实其具有果糖双磷酸醛缩酶活性。细胞分级实验表明，脑膜炎球菌 FBA 定位于细胞质和外膜。流式细胞术表明，外膜定位的 FBA 可被 FBA 特异性抗体接近表面。突变分析和功能互补用于鉴定 FBA 的其他功能。FBA 缺陷突变体在体外生长能力不受影响，但与同源亲本及其互补衍生物相比，对人脑微血管内皮细胞和 HEp-2 细胞的粘附能力显著降低。总之，FBA 是一种高度保守的表面暴露蛋白，是脑膜炎球菌与人细胞最佳粘附所必需的。
