Biomicrofluidics. 2010 Sep 30;4(3):32201. doi: 10.1063/1.3488672.
The control of biofilm formation is a challenging goal that has not been reached yet in many aspects. One unsolved question is the role of van der Waals forces and another is the importance of mutual interactions between the adsorbing and the adsorbed biomolecules ("critical crowding"). In this study, a combined experimental and theoretical approach is presented, which fundamentally probes both aspects. On three model proteins-lysozyme, α-amylase, and bovine serum albumin-the adsorption kinetics is studied experimentally. Composite substrates are used enabling a separation of the short- and the long-range forces. Although usually neglected, experimental evidence is given for the influence of van der Waals forces on the protein adsorption as revealed by in situ ellipsometry. The three proteins were chosen for their different conformational stabilities in order to investigate the influence of conformational changes on the adsorption kinetics. Monte Carlo simulations are used to develop a model for these experimental results by assuming an internal degree of freedom to represent conformational changes. The simulations also provide data on the distribution of adsorption sites. By in situ atomic force microscopy we can also test this distribution experimentally, which opens the possibility to, e.g., investigate the interactions between adsorbed proteins.
生物膜形成的控制是一个具有挑战性的目标，在许多方面尚未实现。一个未解决的问题是范德华力的作用，另一个问题是吸附和被吸附生物分子之间相互作用的重要性（“临界拥挤”）。在这项研究中，提出了一种结合实验和理论的方法，从根本上探测了这两个方面。在三种模型蛋白-溶菌酶、α-淀粉酶和牛血清白蛋白上，实验研究了吸附动力学。使用复合基底，实现了短程和长程力的分离。尽管通常被忽略，但现场椭圆光度法给出了实验证据，表明范德华力对蛋白质吸附的影响。选择这三种蛋白质是因为它们在构象稳定性上的不同，以便研究构象变化对吸附动力学的影响。通过假设内部自由度来代表构象变化，蒙特卡罗模拟被用来为这些实验结果建立一个模型。模拟还提供了关于吸附位点分布的数据。通过原位原子力显微镜，我们也可以实验测试这种分布，这为例如研究吸附蛋白之间的相互作用提供了可能性。
