Copper enzyme cofactor

An enzyme cofactor can be either an inorganic ion (usually a metal cation) or a small organic molecule called a coenzyme. In fact, the requirement of many enzymes for metal-ion cofactors is the main reason behind our dietary need for trace minerals. Iron, zinc, copper, manganese, molybdenum, cobalt, nickel, and selenium are all essential trace elements that function as enzyme cofactors. A large number of different organic molecules also serve as coenzymes. Often, although not always, the coenzyme is a vitamin. Thiamine (vitamin Bj), for example, is a coenzyme required in the metabolism of carbohydrates. 

Iron, copper, zinc, selenium Enzyme cofactors and constituents... 

The chemical rational for the adoption of the d haem ring has not been rigorously determined. Nitrite reduction is one of many examples where biology can use copper or iron. It is striking that no organic cofactor is needed for the copper enzyme. 

Superoxide dismutase (SOD) catalyzes the disproportionation of superoxide to peroxide and oxygen according to equation (2). Four different types of SOD are known, containing either Cu and Zn see Copper Proteins with Type 2 Sites), Fe, Mn, or Ni see Nickel Enzymes Cofactors). The Fe and Mn containing SODs have very similar structures and can be further subdivided into metal-specific (i.e. functioning only when the correct metal is bound) and cambialistic (functioning with either Fe or Mn bound to the active site). 

Active Sites, Copper Proteins Oxidases, Copper Proteins with Type 1 Sites, Copper Proteins with Type 2 Sites, Copper Enzymes in Denitrification, Iron-Sulfur Models of Protein Active Sites, Iron-Sulfur Proteins Nickel Enzymes Cofactors and Nickel Models of Protein Active Sites). However, since many metalloenzymes have been found or postulated to incorporate metal-sulfur bonding, it is appropriate that a very short sununary be included here. 

Chalcogenides Solid-state Chemistry Copper Enzymes in Denitrification Copper Hemocyanin/Tyrosinase Models Copper Proteins Oxidases Copper Proteins with Dinuclear Active Sites Copper Proteins with Type 1 Sites Copper Proteins with Type 2 Sites Iron Sulfitf Models of Protein Active Sites Iron-Snlfiir Proteins Nickel Enzymes Cofactors Nickel Models of Protein Active Sites Polynuclear Organometallic Cluster Complexes. 

Are they involved in carbon metabolism There are many candidates in the carbon metabolism of Prochloron that could be converted to the C3Hs03 moiety of the 2Cu patellamide C complex. Studies have shown that L. patella actively removes glycolate to encourage photosynthesis by prochloron Are the copper complexes of these cyclic peptides involved as enzymic cofactors in this process ... 

A substantial fraction of the named enzymes are oxido-reductases, responsible for shuttling electrons along metabolic pathways that reduce carbon dioxide to sugar (in the case of plants), or reduce oxygen to water (in the case of mammals). The oxido-reductases that drive these processes involve a small set of redox active cofactors , that is, small chemical groups that gain or lose electrons. These cofactors include iron porjDhyrins, iron-sulfur clusters and copper complexes as well as organic species that are ET active. 

A. niger normally produces many useful secondary metabolites citric and oxalic acids are stated as the dominant products. Limitation of phosphate and certain metals such as copper, iron and manganese results in a predominant yield of citric acid. The additional iron may act as a cofactor for an enzyme that uses citric acid as a substrate in the TCA cycle as a result, intermediates of the TCA cycle are formed. 

Copper is an essential trace element. It is required in the diet because it is the metal cofactor for a variety of enzymes (see Table 50—5). Copper accepts and donates electrons and is involved in reactions involving dismu-tation, hydroxylation, and oxygenation. However, excess copper can cause problems because it can oxidize proteins and hpids, bind to nucleic acids, and enhance the production of free radicals. It is thus important to have mechanisms that will maintain the amount of copper in the body within normal hmits. The body of the normal adult contains about 100 mg of copper, located mostly in bone, liver, kidney, and muscle. The daily intake of copper is about 2—A mg, with about 50% being absorbed in the stomach and upper small intestine and the remainder excreted in the feces. Copper is carried to the liver bound to albumin, taken up by liver cells, and part of it is excreted in the bile. Copper also leaves the liver attached to ceruloplasmin, which is synthesized in that organ. 

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