Unité de Chimie des Interfaces, Université Catholique de Louvain, Croix du Sud 2/18, B-1348, Louvain-la-Neuve, Belgium.
Integr Biol (Camb). 2009 Apr;1(4):296-300. doi: 10.1039/b901396b. Epub 2009 Mar 3.
Bacterial surface-associated proteins play essential roles in mediating pathogen-host interactions and represent privileged targets for anti-adhesion therapy. We used atomic force microscopy (AFM) to investigate, in vivo, the binding strength and surface distribution of fibronectin attachment proteins (FAPs) in Mycobacterium bovis bacillus Calmette-Guérin (BCG). We measured the specific binding forces of FAPs ( approximately 50 pN) and found that they increased with the loading rate, as observed earlier for other receptor-ligand systems. We also mapped the distribution of FAPs, revealing that the proteins are widely exposed on the mycobacterial surface. To demonstrate that the proteins are surface-associated, we showed that treatment of the cells with pullulanase, an enzyme possessing carbohydrate-degrading activities, or with protease, an enzyme that conducts proteolysis, led to a substantial reduction of the FAP surface density. A similar trend was also noted following treatment with ethambutol, an antibiotic which inhibits the synthesis of cell wall polysaccharides. The nanoscale analyses presented here complement traditional proteomic and molecular biology approaches for the functional analysis of surface-associated proteins, and may help in the search for novel anti-adhesive drugs.
细菌表面相关蛋白在介导病原体-宿主相互作用方面发挥着重要作用，是抗黏附治疗的理想靶点。我们使用原子力显微镜（AFM）在体内研究了牛分枝杆菌卡介苗（BCG）中纤维连接蛋白附着蛋白（FAP）的结合强度和表面分布。我们测量了 FAP 的特定结合力（约 50 pN），并发现它们随加载速率的增加而增加，这与之前观察到的其他受体-配体系统相同。我们还绘制了 FAP 的分布图谱，揭示了这些蛋白质在分枝杆菌表面广泛暴露。为了证明这些蛋白质是表面相关的，我们表明用普鲁兰酶（一种具有碳水化合物降解活性的酶）或蛋白酶（一种进行蛋白水解的酶）处理细胞会导致 FAP 表面密度显著降低。在用乙胺丁醇（一种抑制细胞壁多糖合成的抗生素）处理后也观察到类似的趋势。这里呈现的纳米级分析补充了传统的蛋白质组学和分子生物学方法，用于表面相关蛋白的功能分析，并可能有助于寻找新型抗黏附药物。
