Theoretical Study On The Mechanism Of Ethanol Oxidation To Aldehyde Catalyzed By Metal Enzyme

The mechanism of ethanol oxidation to aldehyde catalyzed by the liver alcohol dehydrogenase and metal enzyme was studied by density function theory B3LYP method. The optimal structures of reactants, transition states, intermediates and products were located at the B3LYP/6-31G** level of theory. The reaction barriers were then compared in water and in protein at the B3LYP/6-311++G(3df,2p) level of theory. The work of the this paper can be divided in two parts as following:1. The mechanism of ethanol oxidation to aldehyde catalyzed by the liver alcohol dehydrogenase in water and in protein was studied by density function theory B3LYP method. The calculation results show that the high reaction barriers exists for the pathway where no catalyst is involved, suggesting that the oxidation cannot take place at room temperature without catalysts. A low reaction barrier exists when the liver alcohol dehydrogenase is involved, indicating that the liver alcohol dehydrogenase catalyzed reaction can take place at room temperature. The role of the liver alcohol dehydrogenase in the reaction was explored.2. The mechanism of ethanol oxidation to aldehyde catalyzed by metal enzyme in water and in protein was studied by density function theory B3LYP method. We compared the reaction barriers with the different mental enzyme catalysis. The calculation results shown that the activity of metal enzyme would decrease as the increasing of the radius in the same clan and the barriers would increased. The reactions of the calcium and cadmium metal enzyme as catalysts catalyzed the nicotinamide adenine dinucleotide (NAD~+) to oxidate ethanol to aldehyde at room temperature in water can not take place.