Systematic study on the mechanism of aldehyde oxidation to carboxylic acid by cytochrome P450.
The mechanism of aldehyde to carboxylic acid conversion catalyzed by P450 enzymes via a series of reactions was studied systematically for the first time with density functional theory calculations. A two-state reactivity mechanism has been proposed, which can be adopted for many aldehyde oxidation reactions catalyzed by P450 enzymes. The mechanism involves initial hydrogen abstraction as the rate-limiting step and this is followed by steps of oxygen rebound without barriers owing to the quick recombination of the resultant radical species. Meanwhile, in an attempt to explore whether there exist some rules for the hydroxylation of aldehyde substrates by P450, the transition state barriers of the rate-limiting step for a series of aldehyde hydroxylation reactions have been compared. A predictive pattern of extended barrier/bond energy correlation for different hydroxylations of aldehyde substrates by P450 has been established, which was further confirmed to be a reliable reactivity scale by experimental results.
Liu
Xiaojing
X
State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China.
Wang
Yong
Y
Han
Keli
K
D000447:Aldehydes / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D003198:Computer Simulation; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry*; D005557:Formaldehyde / Q000737:chemistry; D006900:Hydroxylation; D008956:Models, Chemical; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013329:Structure-Activity Relationship; D013816:Thermodynamics
D000447:Aldehydes; D002264:Carboxylic Acids; D005557:Formaldehyde; D003577:Cytochrome P-450 Enzyme System