[Quantum chemistry analysis of the mechanism of action of proteolytic enzymes. II. Nucleophilic attack].
Dynamic systems, modelling the elementary act of nucleophilic attack on the carbonyl carbon atom of amide (N-methyl-acetamide) and ester (methylacetate) substrates by some compounds, simulating the nucleophilic group of various types proteases active site were calculated and analysed by the CNDO/2 method, namely: 1) methoxyanion and the methanol (serine proteases), 2) water molecule in the presence of formate anion (carboxylic proteases) and 3) mercaptide anion (CH3S-) (thiolic proteases). The formation of productive enzyme-substrate complex was shown not only to orient reactive groups of the enzyme and substrate, but also to activate it by induction of a certain degree of cleavable pyramidalization, as a result of the partial resonance stabilization energy loss.
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D010447:Peptide Hydrolases / Q000378:metabolism*; D011522:Protons; D011789:Quantum Theory; D013379:Substrate Specificity
D011522:Protons; D010447:Peptide Hydrolases
Kvantovo-khimicheskiĭ analiz mekhanizma deĭstviia proteoliticheskikhfermentov. II. Nukleofil'naia ataka.