Intermolecular forces and enthalpies in the adhesion of Streptococcus mutans and an antigen I/II-deficient mutant to laminin films
Intermolecular forces and enthalpies in the adhesion of Streptococcus mutans and an antigen I/II-deficient mutant to laminin films
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DOI：
10.1128/jb.01731-06
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发表时间：
2007-04-01
影响因子：
3.2
通讯作者：
van der Mei, Henny C.
中科院分区：
文献类型：
--
作者：
Busscher, Henk J.;van de Belt-Gritter, Betsy;van der Mei, Henny C.
表面蛋白抗原 I/II 家族由大多数口腔链球菌（包括变形链球菌）表达，并介导对唾液膜和细胞外基质蛋白等的特异性粘附。在这项研究中，我们表明，与亲本菌株LT11（21.8 x 10（6）和6.8）相比，抗原I / II缺陷的变形链球菌同基因突变体IB03987由于缺乏特异性相互作用（pH 5.8和6.8分别为0.8 x 10（6）和1.1 x 10（6）细胞cm（-2）），在流动条件下几乎无法粘附层粘连蛋白膜。 26.1 x 10(6) 细胞厘米(-2))。亲本菌株和突变菌株在 pH 6.8 时的粘附力均略高于在 pH 5.8 时的粘附力。此外，原子力显微镜（AFM）实验表明，亲本菌株在接近层粘连蛋白薄膜时所经历的排斥力比突变体所经历的排斥力要小。回缩后，亲本菌株的特异性和非特异性结合力（在 pH 5.8 和 6.8 下分别高达 -5.0 和 -4.9 nN）比突变体（高达 -1.5 和 -2.1 nN）更强，突变体只能通过非特异性相互作用相互作用。层粘连蛋白吸附到亲本菌株表面时释放焓，但层粘连蛋白吸附到IB03987表面时不释放焓。将 AFM 中的粘附力与报道的特定配体-受体复合物的粘附力进行比较得出的结论是，变形链球菌 LT11 上层粘连蛋白的抗原 I/II 结合位点的数量约为每个生物体 6 x 10(4) 个位点，并且这些位点可能沿着外表面结构排列，如通过免疫电子显微镜观察到的。
The antigen I/II family of surface proteins is expressed by most oral streptococci, including Streptococcus mutans, and mediates specific adhesion to, among other things, salivary films and extracellular matrix proteins. In this study we showed that antigen I/II-deficient S. mutans isogenic mutant IB03987 was nearly unable to adhere to laminin films under flow conditions due to a lack of specific interactions (0.8 x 10(6) and 1.1 x 10(6) cells cm(-2) at pH 5.8 and 6.8, respectively) compared with parent strain LT11 (21.8 x 10(6) and 26.1 x 10(6) cells cm(-2)). The adhesion of both the parent and mutant strains was slightly greater at pH 6.8 than at pH 5.8. In addition, atomic force microscopy (AFM) experiments demonstrated that the parent strain experienced less repulsion when it approached a laminin film than the mutant experienced. Upon retraction, combined specific and nonspecific adhesion forces were stronger for the parent strain (up to -5.0 and -4.9 nN at pH 5.8 and 6.8, respectively) than for the mutant (up to -1.5 and -2.1 nN), which was able to interact only through nonspecific interactions. Enthalpy was released upon adsorption of laminin to the surface of the parent strain but not upon adsorption of laminin to the surface of IB03987. A comparison of the adhesion forces in AFM with the adhesion forces reported for specific ligand-receptor complexes resulted in the conclusion that the number of antigen I/II binding sites for laminin on S. mutans LT11 is on the order of 6 x 10(4) sites per organism and that the sites are probably arranged along exterior surface structures, as visualized here by immunoelectron microscopy.