Mechanism Of Enzyme Catalysis And Protein Folding

The studies about the mechanism of enzyme catalysis and protein folding, belonging to protein structure and function, may be divided into two parts: (1) Preparation of artificial enzymes by bio-imprinting; and (2) Recognition between two-state and three-state fomding kinetics. The former is based on experimental technology; the latter is a theortical research.In the preparation of bio-imprinted enzymes, two bio-imprinting approaches are available: (1) bio-imprinting of egg albumin using heat-denaturalization; and (2) bio-imprinting of egg albumin using bovine serum albumin using dissolving-precipitation process. Moreover, Herring sperm DNA is bio-imprinted using the dissolving-precipitation process. The substrate templates are Benzoyl-arginine-OEt, Benzoyl- L-arginine-p-nitroanilide and Benzoyl-L-arginine-OH.Catalytic activities of these artificial enzymes are tested by using UV-vis spectrum. The results show that the three mimics imprinted by the two techniques have enzymatic power, suggesting that a large number of efficient active cavities are formed within these bio-macromolculaes. Herring sperm DNA also exhibit the catalytic power for hydrolysis. These indicat that nucleic acids are created the active cavities to become an enzyme, besides natural protein and ribozymes.In theortical research of protein folding, proteins are different in folding rate, intermedium and folding mechanism because of different of folding kinetic passways. Recognition between the folding passways is basis of kineics of protein folding. Here we used logstic regressions and support vect machine to recognize between two-state and three-state folding kinetics. We observed that three-state folding proteins can be recognized using chain length. 112 residues are boundary between two-state and three-state proteins. If length is markedly lower than 112 residues, the protein preferentially folds with two-state kinetics. If much more than 112 residues, multi-state folding is considered a more effective competitor. One cannot decides whether the～112-residue proteins. The predictions from sequence show that cysteine, tryptophan, phenylalanine, arginine and lysine play an important role in folding kinetic pathways, and the reason is that disulfide bridge and hydrophobic interaction stabilize intermediates, thereby resulting in three-state folding behavior.