ABSTRACT
According to biochemists, there are some “perfect enzymes.” In this chapter, we argue that perfect enzymes did not reach the end of their natural evolutionary development despite the truly amazing enhancement of the reaction rate in their presence. The performance parameters of interest are the catalytic constant or turnover number, and the catalytic efficiency or specificity constant. We used the maximal transitional entropy production theorem to examine how rate-limiting steps of a catalytic cycle can be identified and optimized for the triosephosphate isomerase and beta-lactamase enzymes. Proton transfer is often the critical transition step induced by substrate binding to the enzyme. Just like macroscopic currents, these enzyme-localized nanocurrents are also accompanied by increased overall entropy production. Moreover, evolutionary more evolved enzymes exhibit a concomitant increase in their performance parameters and generated entropy.
