Grubmüller H, Heymann B, Tavan P
Theoretische Biophysik, Institut für Medizinische Optik, Ludwig- Maximilians-Universität München, Germany. Helmut.Grubmueller@ Physik.uni-muenchen.de
Science. 1996 Feb 16;271(5251):997-9. doi: 10.1126/science.271.5251.997.
The force required to rupture the streptavidin-biotin complex was calculated here by computer simulations. The computed force agrees well with that obtained by recent single molecule atomic force microscope experiments. These simulations suggest a detailed multiple-pathway rupture mechanism involving five major unbinding steps. Binding forces and specificity are attributed to a hydrogen bond network between the biotin ligand and residues within the binding pocket of streptavidin. During rupture, additional water bridges substantially enhance the stability of the complex and even dominate the binding interactions. In contrast, steric restraints do not appear to contribute to the binding forces, although conformational motions were observed.
本文通过计算机模拟计算了使链霉亲和素-生物素复合物断裂所需的力。计算得到的力与最近通过单分子原子力显微镜实验获得的结果吻合良好。这些模拟结果表明了一种详细的多途径断裂机制，该机制涉及五个主要的解离步骤。结合力和特异性归因于生物素配体与链霉亲和素结合口袋内残基之间的氢键网络。在断裂过程中，额外的水桥显著增强了复合物的稳定性，甚至主导了结合相互作用。相比之下，尽管观察到了构象运动，但空间位阻似乎对结合力没有贡献。
