Soell Martine, Hemmerlé Joseph, Hannig Matthias, Haïkel Youssef, Sano Hidehiko, Selimovic Denis
Department of Periodontology, Dental Faculty Strasbourg, Hautepierre Hospitals, Strasbourg, University, Strasbourg, France.
Eur J Oral Sci. 2010 Dec;118(6):590-5. doi: 10.1111/j.1600-0722.2010.00785.x.
Viridans streptococci possess a family of immunologically and structurally related cell-surface proteins, termed antigen I/II, which may function as adhesins and enable oral streptococci to adhere to saliva-coated surfaces and matrix proteins. Here we used atomic force microscopy in the molecular force mode to measure the specific interaction forces between antigen I/II and two matrix proteins, collagen and fibronectin. These matrix proteins provide important binding sites for adherence of oral streptococcal in dentinal caries and endocarditis, respectively. Antigen I/II-coated cantilever tips were brought into contact with collagen- or fibronectin-coated silica coverslips. For the protein I/II-fibronectin interaction experiments, the mean strength of the last ruptures was 216 pN, with most of the detachments located around 125 pN. In antigen I/II-collagen interaction experiments, the mean strength of the last rupture forces corresponded to 136 pN, with the most frequent unbinding force around 75 pN. Thus, our findings definitely suggest that, under the present experimental conditions, antigen I/II binds more strongly to fibronectin than to type I collagen. This might be of relevance for the attachment of viridians streptococci to surfaces exposed to strong hydrodynamic shearing forces under in vivo conditions.
草绿色链球菌拥有一族在免疫学和结构上相关的细胞表面蛋白，称为抗原I/II，它们可能作为黏附素发挥作用，使口腔链球菌能够黏附于唾液包被的表面和基质蛋白。在此，我们使用分子力模式下的原子力显微镜来测量抗原I/II与两种基质蛋白（胶原蛋白和纤连蛋白）之间的特异性相互作用力。这些基质蛋白分别为口腔链球菌在牙本质龋和心内膜炎中的黏附提供重要的结合位点。将包被有抗原I/II的悬臂尖端与包被有胶原蛋白或纤连蛋白的二氧化硅盖玻片接触。对于蛋白I/II - 纤连蛋白相互作用实验，最后断裂的平均强度为216皮牛，大多数解离发生在125皮牛左右。在抗原I/II - 胶原蛋白相互作用实验中，最后断裂力的平均强度相当于136皮牛，最频繁的解离力约为75皮牛。因此，我们的研究结果明确表明，在当前实验条件下，抗原I/II与纤连蛋白的结合比与I型胶原蛋白的结合更强。这可能与草绿色链球菌在体内条件下黏附于承受强大流体动力剪切力的表面有关。
