Introduction to reductase

A reductase refers to an enzyme that catalyzes the hydrogenation of a substrate. Such as nitrate reductase, nitrite reductase, hydrogenase and N5, N10 - methylenetetrahydrofolate reductase (FAD) and so on.

Classification of reductase

Oxidoreductase description: can catalyze the two molecules between the oxidation and reduction of enzymes in general. The oxidase (oxydase) can catalyze the oxidation of substances by the role of oxygen, dehydrogenase can catalyze the removal of hydrogen from the role of material molecules. Mainly in the cells.

Oxidoreductases catalyze the oxidation or reduction of the substrate, which requires an electron donor or acceptor. Numerous oxidoreductases in the body require the use of coenzyme NAD (nicotinamide adenine dinucleotide) or NDAP (nicotinamide adenine dinucleotide phosphate) and FAD (flavin adenine dinucleotide) or FMN (flavin mononucleotide). Of course, some enzymes do not need coenzyme or cofactor, directly to oxygen as electron transfer body, such as glucose oxidase.

Nitrite reductase: assimilates the nitrification of the nitrite reductase with siroheme (see sulfite reductase), the reduction of 6 electrons to produce ammonia. Higher plants, green algae and cyanobacteria to ferritin reducing protein as an electron donor. Higher plants exist only in chloroplasts or precursors. Spinach leaves the enzyme molecular weight of 60,000, containing siroheme, non-heme iron and acid-labile sulfur. (Molecular weight of 290,000) and Escherichia coli (190,000, EC 1.6.6.4) containing FAD, non-heme iron and siroheme, and NAD (N-methyl-N-acetyl-NAD) (P) H is an electron donor. Dissociated enzymes participate in the process of oxidizing organic matter with nitrite, in which the enzymes of the denitrifying bacteria produce NO, which is reduced to N2 by the action of other reductases. Denitrifying bacteria have two kinds of nitrite reductase, a copper protein, with cytochrome C as the electron donor (EC1.7.2.1) (Alcaligenes faecalis). The other for the cytochrome c and d, can act as enzymes, but also has the role of cytochrome oxidase (Pseudomonasaeruginosa, Afacealis). There are C-containing hemoglobin, the cytochrome electron donor to produce NH4 + nitrite reductase, present in the Achromobacter chromosum (Achromoba-cterfischeri). In addition, sulfite reductase also has more nitrite reduction activity.

Sulfite reductase: can be divided into two types, namely, higher plants, algae and bacteria assimilation of sulphate assimilation and sulfuric acid-reducing bacteria, including sulfuric acid bacteria and sulfuric acid oxidation sulfide alienation. Type II each with a unique heme, mostly brown. The heme according to the abbreviation SiR of this enzyme is called siroheme, the deferrization compounds (sirohy-drochlorin) is the synthesis of vitamin B12 in vivo intermediates from urinary porphyrinogen generation. NADPH is the electron donor for the enzyme (EC18.1.2) of E.coli, Saccharomyces and Asperg-illus. Containing FAD, FMN, non-heme iron (sulfide) and siroheme, in this order in the electron transfer to produce H2S. In addition, also play a role in reducing cytochrome c. Spinach enzyme monomeric molecular weight of 13.6 million to ferredoxin as the electron donor, also generates sulfide. In addition to producing sulfides, the isomerized enzyme also produces thiosulfate or trisulphide (S3O62-). Desulfovibrio enzyme molecular weight of 240,000, green, known as desulfoflavin, that is based on cytochrome c3 as the electron donor. 

Reductase related knowledge

【Reduction】

Reduction by chemical or electrochemical methods of the following actions or processes: remove the non-metallic elements to produce metal; from a substance to remove oxygen; with hydrogen or hydrogen; with the lower part of the electronegativity ratio of a change in some compounds; Change an element or ion from a higher oxidation state to a lower oxidation state; add one or more electrons to an atom.

【Enzyme】

A biocatalyst produced by cells in an organism. By the protein composition (minority of RNA). Can be very mild in the body under the conditions of high efficiency to catalyze a variety of biochemical reactions, and promote the metabolism of organisms. Digestion, absorption, respiration, and reproduction in life activities are all enzymatic reactions. Enzymes are the basis of cell survival. Almost all the chemical reactions involved in cell metabolism are catalyzed by the enzyme. Mammalian cells contain thousands of enzymes. They are either dissolved in the cytosol, attached to a variety of membrane structures, or located at specific locations within other structures within the cell. These enzymes collectively referred to as intracellular enzymes; In addition, there are some in the cell after synthesis and secretion of extracellular enzymes - extracellular enzymes. Enzyme catalytic chemical reaction ability called enzyme activity (or enzyme activity). Enzyme activity can be controlled by a variety of factors, so that the organism can adapt to changes in external conditions, to maintain life activities. Without the participation of enzymes, metabolism can only be carried out at an extremely slow pace, life activities simply can not be maintained. For example, food must be degraded into small molecules under the action of enzymes in order to pass through the intestinal wall and be absorbed and utilized by the tissue. There are pepsin in the stomach, pancreatic secretion in the intestine of trypsin, chymotrypsin, lipase and amylase. Another example is the oxidation of food is the source of animal energy, the oxidation process is in a series of enzyme catalysis completed.

Enzyme Catalysis Substance: reduces activation energy of chemical reaction on