Sulfur dioxygen activation

In order to sustain catalysis, the P450 enzymes require a reductase to supply two additional electrons from NAD(P)H needed for dioxygen activation. The nature of the reductase varies depending on the specific P450, ranging from self-contained redox cofactors such as FAD and FMN present in the same protein as the iron-heme cofactor to multi-protein systems in which separate proteins containing redox cofactors such as FAD and iron-sulfur clusters perform the electron-transfer function [12]. 

An essential step in the mechanism of dioxygen activation is the electron transfer from the reduced pyridine nucleotide to the hemoprotein. So far, two principally different reducing systems have been found. One occurs in bacteria and mitochondria and contains an FAD-flavoprotein together with an iron-sulfiir protein. The second consists of an FAD-FMN flavoprotein which directly reduces the hemoprotein without the help of an iron-sulfur protein (Fig. 6). 

Biomineralization Iron Heme Proteins Dioxygen Transport Storage Iron Heme Proteins Electron Transport Iron Heme Proteins, Mono- Dioxygenases Iron Heme Proteins, Peroxidases, Catalases Catalase-peroxidases Iron Inorganic Coordination Chemistry Iron Proteins with Dinuclear Active Sites Iron Proteins with Mononuclear Active Sites Iron-Sulfur Proteins Iron Transport Siderophores Metal Ion Toxicity. 

Potentially explosive reaction with nitric acid + sulfuric acid, bromine trifluoride, nitrosyl chloride + platinum, nitrosyl perchlorate, chromyl chloride, thiotrithiazyl perchlorate, and (2,4,6-trichloro-l, 3,5-triazine + water). Reacts to form explosive peroxide products with 2-methyl-1,3-butadiene, hydrogen peroxide, and peroxomonosulfuric acid. Ignites on contact with activated carbon, chromium trioxide, dioxygen difluoride + carbon dioxide, and potassium-tert-butoxide. Reacts violendy with bromoform, chloroform + alkalies, bromine, and sulfur dichloride. 

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