Measuring a Stabilization Constant Between Two Bio-Molecules using Atomic Force Microscopy

Abstract

Stabilization force constants are known to play an important role in biomolecular functions that carry out delicate structural conformation changes along a reaction coordinate during bio-molecular activation. Atomic force microscopy (AFM) has been used as a tool for probing protein-ligand interactions at the single molecular level. We developed a method that converts AFM force-distance curves into intermolecular force-distance curves. This method was applied to a model enzyme-inhibitor system of 5’ methylthioadenosine/S-adenosylhomocysteine nucleo-sidase (MTN) and its transition state analogue homocysteinyl Immucillin A (HIA).