THERMODYNAMIC TRAJECTORY OF ENZYME EVOLUTION

The trajectory of enzyme evolution is estimated from the relationship between the overall enthalpy of activation and overall entropy of acti vation. As evolution proceeds, the trajectory passes a turning point a nd then go toward diffusion-controlled region. Thus, the following two possibilities are put forth as candidates of a goal of evolution. One is that evolution will stop at a turning point, where specificity of a reaction is highest. The other is that the ultimate goal of evolutio n is the diffusion-controlled reaction, where catalytic efficiency is highest.