Enzymes for oxidations

The DszC enzyme was able to convert the following compounds other than DBT thioxanthen-9-one, 2,8-dimethyl DBT, 4,6-dimethyl DBT, and 3,4-benzo DBT. Non-organosulfur compounds such as biphenyl, carbazole, and dibenzofuran did not show any activity. This indicates that dszC specifically recognizes sulfur atom [151]. One study specifically examined the DszC enzyme for oxidation of aryl sulfides [179] and reported oxidation of many sulfides including, naphthyl methyl sulfide, phenyl methyl sulfide, and its alkyl derivatives. 

A major challenge in chemical and food industry is to perform oxidative and reductive conversions by biological means. In the application of enzymes for oxidative or reductive conversions a coenzyme like NAD(P)H or FADH2 is needed. For two... 

The catalytically active form of the enzyme for oxidation is believed to be a haem oxo-iron(IV) porphyrin radical cation, called Compound I. The key step in substrate oxidation involves hydrogen atom abstraction or C=C bond addition by the oxygen... 

Isolated single enzymes have the potential advantage of totally specific transformations. However this is often offset by disadvantages such as instability, the need to add or recycle cofactors, and the difficulty in obtaining suitable enzymes for oxidation of unactivated C—systems. 

The iodination with lactoperoxidase is also very gentle and very often used Because the application of an enzyme for oxidation is more expensive than the use of common oxidation reagents, procedures involving immobilized lactoperoxidase have been worked out 21.22.26)... 

We can compare this protein with a Cu metallo-enzyme for oxidation using molecular oxygen (e.g., laccase). The reaction is the generation of a free radical from a substrate X, say ascorbic acid, by removal of electrons at a single-copper site and transfer of the electron to a distant three-copper site where oxygen is reduced to water by four successive additions of single electrons. Now the three-copper site must be open sided to give access to O2, but the substrate to be oxidized by one of the electron-transfer steps can be as far away as a reasonable electron-transfer rate will permit, 10-15A, from the second. 

E S. Sariaslaiti, Microbial enzymes for oxidation of organic molecules, Crit. Rev. Biotedi., 9 171 (1989). 

Mitochondria None enzymes for oxidation reactions located on plasma membrane Present... 

FoMy Acid Oxidation by Cell-Free Preparations. An important development in the study of fatty acid oxidation was made by Munoz and Leloir, who found that homogenates of liver oxidize fatty acids when supplemented with adenine nucleotides, inorganic phosphate, Mg++, cytochrome c (a compoimd involved in electron transport), and a member of the tricarboxylic acid cycle. Others found that washed mitochondria contain all the necessary enzymes for oxidation of fatty acids to either CO2 or acetoacetate, provided the supplements of Munoz and Leloir were added. Such systems are extremely delicate, and for many years it was considered that maintenance of the intact structure of mitochondria was essential for preservation of fatty acid oxidation. 

Extracts of Cl. hlvyveri contain the fuU complement of enzymes for oxidative conversion of butyrate to equal parts of acetyl phosphate and acetate. The studies of Barker and Stadtman have led to the following formulation of the reaction mechanism ... 

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