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Oxidation-reduction reaction (oxidation-reduction reaction, also for the redox reaction) is one of the basic and important reaction types in vivo, the nature of the reaction of electron transfer, but the amino acid itself does not have good cons electron capacity, so the vast majority oxidoreductase catalytic reaction requires the participation of the cofactor (cofactor). Cofactor combined with the enzyme and is necessary for the catalytic reaction of the non-protein-based compound, mainly including the following two categories: organic cofactor nicotinamide adenine dinucleotide (NAD), nicotinamide adenine dinucleotide nucleotide phosphate (NADP), flavin adenine dinucleotide (FMN), flavin adenine dinucleotide (FAD), etc.; metal cofactor, such as zinc (Zn), iron (Fe), manganese (Mn ), nickel (Ni), cobalt (Co). Because these two types of cofactors are the pros and cons of electronic, it is necessary to study the oxidoreductase cofactor use of the above two categories whether the select preferences and to explore this preference possible causes. In this thesis, the integrated use of bioinformatics methods and chemical informatics methods research and analysis of in vivo oxidation-reduction reaction. First, the cofactor usage by all oxidation statistical SWISS-PROT/TrEMBL database reductase (EC 1._._._), (a total of 1151 enzyme number), according to the use type of the cofactor will oxidoreductase stars into two categories: the use of small organic molecules as the organic cofactor enzyme and the use of metal ions as metal enzyme cofactor. Oxidoreductase organic cofactor frequency of use (76.1%) is much higher than the metal the cofactors (14.3%); Secondly, in order to explain the oxidoreductase cofactor preferences, we selected 41 species and by bioinformatics methods a statistical analysis of the frequency of its use in vivo oxidoreductase cofactor found that about 90% of an oxidoreductase in the ancient eukaryotes and prokaryotes vivo using an organic cofactor, approximately 78% of the eukaryotes redox enzyme using an organic cofactors. To further explain the above phenomenon, the one hand, an oxidoreductase catalytic reaction equation analysis found that the reaction of approximately 28.5% of the organic enzymes require oxygen to participate directly in the metal enzymes approximately 63.2%, and Therefore, we infer that the oxygen appears may lead to the the metal cofactor elevated frequency of use of the important reason; the other hand, chemical informatics methods of redox reactions involving small molecules were the chemical nature of the analysis, found that the the metalloenzymes group prefer to use hydrophobic of small molecules, therefore, we infer oxidoreductase choose to use the metal cofactor in order to more conducive to the reaction environment within the hydrophobic cell.
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