DIRECTED EVOLUTION FOR THE DESIGN OF NEW CATALYSTS

Introducing new catalytic function into existing proteins provide ways of understanding the fundamental principles of enzyme catalysis and has gained recognition as a leading tool for understanding protein folding, structure, and function. De novo computational design coupled with directed evolution can yield catalysts with novel functions and improved catalytic rate enhancement of enzymes.1-2 Minimalist protein design that focuses on the bare minimum requirements to achieve activity presents several important advantages. By utilizing basic physico-chemical properties and strategic placing of only few highly active residues one can feasibly sample a very large variety of possible catalysts. In more general terms minimalist approach looks for the mere possibility of catalysis, rather than trying to identify the most active catalyst possible. Even very basic designs that utilize a single residue introduced into non-enzymatic proteins or peptide bundles are surprisingly active. No complex calculations need to be set up and even a beginner can master this technique in a very short time. An enzyme nicknamed AlleyCatE is an allosterically regulated catalyst of ester hydrolysis that was generated by introducing a single histidine residue into a non-enzymatic protein calmodulin (CaM). The catalytic efficiency of the resulting enzyme is higher than that of any other rationally designed p-nitrophenylesterase and is on par with some catalytic antibodies