What functional groups are in biotin?
Evidence accounting for the functional groups of biotin has been presented. It has been concluded that biotin is a carboxylic acid containing an N ,N’-substituted cyclic urea grouping and possess- ing sulfur in a thio ether linkage.
Does biotin transfer carboxyl?
The overall reaction is composed of two distinct half reactions; the ATP-dependent carboxylation of biotin with bicarbonate to form carboxybiotin followed by transfer of the carboxyl group from carboxybiotin to acetyl-CoA to form malonyl-CoA (Fig. 4).
Which is the coenzyme of vitamin biotin?
Biotin as the coenzyme biocytin functions in carboxylation reactions that convert odd-carbon-numbered amino acids and fatty acids to even-carbon-numbered compounds, which can then be metabolized. Biocytin is also necessary for the synthesis of pyrimidines and the formation of urea.
Which enzyme uses biotin as coenzyme?
Biotin is a coenzyme for five carboxylase enzymes, which are involved in the digestion of carbohydrates, synthesis of fatty acids, and gluconeogenesis. Biotinylation of histone proteins in nuclear chromatin plays a role in chromatin stability and gene expression.
What elements make up biotin?
Biotin is an organic heterobicyclic compound that consists of 2-oxohexahydro-1H-thieno[3,4-d]imidazole having a valeric acid substituent attached to the tetrahydrothiophene ring. The parent of the class of biotins.
What metabolic pathways use biotin?
In humans, biotin is involved in important metabolic pathways such as gluconeogenesis, fatty acid synthesis, and amino acid catabolism by acting a as prosthetic group for pyruvate carboxylase, propionyl-CoA carboxylase, beta-methylcrotinyl-CoA carboxylase, and acetyl-CoA carboxylase.
Are all carboxylase biotin-dependent?
Biotin-dependent carboxylases can be classified first based on the identity of the substrate that becomes carboxylated. This is dictated by the CT component, which can be highly distinct among these enzymes (Fig….Table 2.
| Organism | Biotin-dependent carboxylase (family number) |
|---|---|
| Escherichia coli K-12 | Multi-subunit ACC (1.1) |
What is coenzyme of biotin?
Biotin is a water-soluble B-vitamin, also called vitamin B7 and formerly known as vitamin H or coenzyme R. Biotin is a coenzyme for carboxylase enzymes, involved in the synthesis of fatty acids, isoleucine, and valine, and in gluconeogenesis.
How is biotin produced?
Biotin is a water-soluble vitamin. That means it’s not stored in your body for long. Your body doesn’t naturally produce it, either. However, the bacteria in your gut can produce biotin.
Is vitamin B8 the same as biotin?
Vitamin B7, also known as biotin, vitamin H or vitamin B8, is a water-soluble vitamin, required by all organisms and is classified as a B-complex vitamin.
What is the role of biotin in carboxylases?
Biotin has long been recognized for its role as a covalently bound coenzyme for carboxylases [11]. More recently, evidence emerged that biotin also plays unique roles in cell signaling, epigenetic regulation of genes, and chromatin structure [12]. 3.1. Biotin-dependent carboxylases
Which is a valeric acid substituent in biotin?
Biotin is a water-soluble B-complex vitamin which is composed of an ureido ring fused with a tetrahydrothiophene ring. A valeric acid substituent is attached to one of the carbon atoms of the tetrahydrothiophene ring. Biotin is used in cell growth, the production of fatty acids, metabolism of fats, and amino acids.
Why is biotin important in branched chain amino acid catabolism?
Biotin is important in fatty acid synthesis, branched-chain amino acid catabolism, and gluconeogenesis. It covalently attaches to the epsilon-amino group of specific lysine residues in these carboxylases.
How is biotin covalently coupled to a protein?
Biotin is covalently coupled to a 16.7 kDa protein called biotin carboxyl carrier protein (BCCP). The biotin must be coupled to BCCP for acetyl-CoA carboxylase to function, and the coupling reaction is catalyzed by a specific enzyme, biotin-apoprotein ligase.