ABSTRACT
The adhesion force measurement reported in this study clearly demonstrates an important role of hydrogen bonding in adhesion interactions. Whenever there is a potential for hydrogen bonding, a strong adhesional contact is observed, although long-range electrostatic and short-range hydration repulsion also play vital roles. Translating these insights into folding of protein molecules in a biological system, it is desirable to eliminate intra-chain hydrogen bonding and to maximize hydration and electrostatic repulsion. This can be accomplished collectively by increasing surface charge densities of carboxylic acid groups, for example, with increasing solution pH or protonation of amine groups with decreasing solution pH.
