Corrin is a heterocyclic compound. Although not known to exist on its own, the molecule is of interest as the parent macrocycle related to the cofactor and chromophore in vitamin B12. Its name reflects that it is the "core" of vitamin B12 (cobalamins). Compounds with a corrin core are known as "corrins".
Metalloprotein is a generic term for a protein that contains a metal ion cofactor. A large proportion of all proteins are part of this category. For instance, at least 1000 human proteins contain zinc-binding protein domains although there may be up to 3000 human zinc metalloproteins.
Thiocyanate is the anion [SCN]−, a salt or an ester of thiocyanic acid. It is the conjugate base of thiocyanic acid. Common derivatives include the colourless salts potassium thiocyanate and sodium thiocyanate. Mercury(II) thiocyanate was formerly used in pyrotechnics.
Bioinorganic chemistry is a field that examines the role of metals in biology. Bioinorganic chemistry includes the study of both natural phenomena such as the behavior of metalloproteins as well as artificially introduced metals, including those that are non-essential, in medicine and toxicology. Many biological processes such as respiration depend upon molecules that fall within the realm of inorganic chemistry. The discipline also includes the study of inorganic models or mimics that imitate the behaviour of metalloproteins.
Methylcobalamin (mecobalamin, MeCbl, or MeB12) is a cobalamin, a form of vitamin B12. It differs from cyanocobalamin in that the cyano group at the cobalt is replaced with a methyl group. Methylcobalamin features an octahedral cobalt(III) centre and can be obtained as bright red crystals. From the perspective of coordination chemistry, methylcobalamin is notable as a rare example of a compound that contains metal–alkyl bonds. Nickel–methyl intermediates have been proposed for the final step of methanogenesis.
Hydroxocobalamin, also known as vitamin B12a and hydroxycobalamin, is a vitamin found in food and used as a dietary supplement. As a supplement it is used to treat vitamin B12 deficiency including pernicious anemia. Other uses include treatment for cyanide poisoning, Leber's optic atrophy, and toxic amblyopia. It is given by injection into a muscle or vein.
Nitrile hydratases are mononuclear iron or non-corrinoid cobalt enzymes that catalyse the hydration of diverse nitriles to their corresponding amides
Cobalamin riboswitch is a cis-regulatory element which is widely distributed in 5' untranslated regions of vitamin B12 (Cobalamin) related genes in bacteria.
In enzymology, a precorrin-8X methylmutase is an enzyme that catalyzes the chemical reaction
Cobalt chelatase (EC 6.6.1.2) is an enzyme that catalyzes the chemical reaction
Vitamin B12, also known as cobalamin, is a water-soluble vitamin involved in metabolism. It is one of eight B vitamins. It is required by animals, which use it as a cofactor in DNA synthesis, and in both fatty acid and amino acid metabolism. It is important in the normal functioning of the nervous system via its role in the synthesis of myelin, and in the circulatory system in the maturation of red blood cells in the bone marrow. Plants do not need cobalamin and carry out the reactions with enzymes that are not dependent on it.
Cyanocobalamin is a form of vitamin B
12 used to treat vitamin B
12 deficiency except in the presence of cyanide toxicity. The deficiency may occur in pernicious anemia, following surgical removal of the stomach, with fish tapeworm, or due to bowel cancer. It is less preferred than hydroxocobalamin for treating vitamin B
12 deficiency. Some study have shown that it has an antihypotensive effect. It is used by mouth, by injection into a muscle, or as a nasal spray.
Organocobalt chemistry is the chemistry of organometallic compounds containing a carbon to cobalt chemical bond. Organocobalt compounds are involved in several organic reactions and the important biomolecule vitamin B12 has a cobalt-carbon bond. Many organocobalt compounds exhibit useful catalytic properties, the preeminent example being dicobalt octacarbonyl.
Cobalt is a chemical element with the symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver metal.
The total synthesis of the complex biomolecule vitamin B12 was accomplished in two different approaches by the collaborating research groups of Robert Burns Woodward at Harvard and Albert Eschenmoser at ETH in 1972. The accomplishment required the effort of no less than 91 postdoctoral researchers (Harvard: 77, ETH: 14), and 12 Ph.D. students (at ETH) from 19 different nations over a period of almost 12 years. The synthesis project induced and involved a major change of paradigm in the field of natural product synthesis.
In molecular biology, the vitamin B12-binding domain is a protein domain which binds to cobalamin. It can bind two different forms of the cobalamin cofactor, with cobalt bonded either to a methyl group (methylcobalamin) or to 5'-deoxyadenosine (adenosylcobalamin). Cobalamin-binding domains are mainly found in two families of enzymes present in animals and prokaryotes, which perform distinct kinds of reactions at the cobalt-carbon bond. Enzymes that require methylcobalamin carry out methyl transfer reactions. Enzymes that require adenosylcobalamin catalyse reactions in which the first step is the cleavage of adenosylcobalamin to form cob(II)alamin and the 5'-deoxyadenosyl radical, and thus act as radical generators. In both types of enzymes the B12-binding domain uses a histidine to bind the cobalt atom of cobalamin cofactors. This histidine is embedded in a DXHXXG sequence, the most conserved primary sequence motif of the domain. Proteins containing the cobalamin-binding domain include:
In molecular biology, cob(I)yrinic acid a,c-diamide adenosyltransferase EC 2.5.1.17 is an enzyme which catalyses the conversion of cobalamin into one of its coenzyme forms, adenosylcobalamin. Adenosylcobalamin is required as a cofactor for the activity of certain enzymes. AdoCbl contains an adenosyl moiety liganded to the cobalt ion of cobalamin via a covalent Co-C bond.
Cobalamin biosynthesis is the process by which bacteria and archea make cobalamin, vitamin B12. Many steps are involved in converting aminolevulinic acid via uroporphyrinogen III and adenosylcobyric acid to the final forms in which it is used by enzymes in both the producing organisms and other species, including humans who acquire it through their diet.
Cobalt-precorrin-5B (C1)-methyltransferase (EC 2.1.1.195), cobalt-precorrin-6A synthase, CbiD (gene)) is an enzyme with systematic name S-adenosyl-L-methionine:cobalt-precorrin-5B (C1)-methyltransferase. This enzyme catalyses the following chemical reaction
Cobalt is essential to the metabolism of all animals. It is a key constituent of cobalamin, also known as vitamin B12, the primary biological reservoir of cobalt as an ultratrace element. Bacteria in the stomachs of ruminant animals convert cobalt salts into vitamin B12, a compound which can only be produced by bacteria or archaea. A minimal presence of cobalt in soils therefore markedly improves the health of grazing animals, and an uptake of 0.20 mg/kg a day is recommended because they have no other source of vitamin B12.
