Biotin (BioDeep_00000000743)

描述信息

Biotin (also known as vitamin B7 or vitamin H) is one of the B vitamins.[1][2][3] It is involved in a wide range of metabolic processes, both in humans and in other organisms, primarily related to the utilization of fats, carbohydrates, and amino acids.[4] The name biotin, borrowed from the German Biotin, derives from the Ancient Greek word βίοτος (bíotos; 'life') and the suffix "-in" (a suffix used in chemistry usually to indicate 'forming').[5] Biotin appears as a white, needle-like crystalline solid.[6]

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. It has a role as a prosthetic group, a coenzyme, a nutraceutical, a human metabolite, a Saccharomyces cerevisiae metabolite, an Escherichia coli metabolite, a mouse metabolite, a cofactor and a fundamental metabolite. It is a member of biotins and a vitamin B7. It is a conjugate acid of a biotinate.
A water-soluble, enzyme co-factor present in minute amounts in every living cell. It occurs mainly bound to proteins or polypeptides and is abundant in liver, kidney, pancreas, yeast, and milk.
Biotin is a metabolite found in or produced by Escherichia coli (strain K12, MG1655).
Biotin is a natural product found in Lysinibacillus sphaericus, Aspergillus nidulans, and other organisms with data available.
Biotin is hexahydro-2-oxo-1H-thieno(3,4-d)imidazole-4-pentanoic acid. Growth factor present in minute amounts in every living cell. It occurs mainly bound to proteins or polypeptides and is abundant in liver, kidney, pancreas, yeast, and milk. The biotin content of cancerous tissue is higher than that of normal tissue.
Biotin is an enzyme co-factor present in minute amounts in every living cell. Biotin is also known as vitamin H or B7 or coenzyme R. It occurs mainly bound to proteins or polypeptides and is abundant in liver, kidney, pancreas, yeast, and milk. Biotin has been recognized as an essential nutrient. Our biotin requirement is fulfilled in part through diet, through endogenous reutilization of biotin and perhaps through capture of biotin generated in the intestinal flora. The utilization of biotin for covalent attachment to carboxylases and its reutilization through the release of carboxylase biotin after proteolytic degradation constitutes the biotin cycle. Biotin deficiency is associated with neurological manifestations, skin rash, hair loss and metabolic disturbances that are thought to relate to the various carboxylase deficiencies (metabolic ketoacidosis with lactic acidosis). It has also been suggested that biotin deficiency is associated with protein malnutrition, and that marginal biotin deficiency in pregnant women may be teratogenic. Biotin acts as a carboxyl carrier in carboxylation reactions. There are four biotin-dependent carboxylases in mammals: those of propionyl-CoA (PCC), 3-methylcrotonyl-CoA (MCC), pyruvate (PC) and acetyl-CoA carboxylases (isoforms ACC-1 and ACC-2). All but ACC-2 are mitochondrial enzymes. The biotin moiety is covalently bound to the epsilon amino group of a Lysine residue in each of these carboxylases in a domain 60-80 amino acids long. The domain is structurally similar among carboxylases from bacteria to mammals. There are four biotin-dependent carboxylases in mammals: those of propionyl-CoA (PCC), 3-methylcrotonyl-CoA (MCC), pyruvate (PC) and acetyl-CoA carboxylases (isoforms ACC-1 and ACC-2). All but ACC-2 are mitochondrial enzymes. The biotin moiety is covalently bound to the epsilon amino group of a Lys residue in each of these carboxylases in a domain 60-80 amino acids long. The domain is structurally similar among carboxylases from bacteria to mammals. Evidence is emerging that biotin participates in processes other than classical carboxylation reactions. Specifically, novel roles for biotin in cell signaling, gene expression, and chromatin structure have been identified in recent years. Human cells accumulate biotin by using both the sodium-dependent multivitamin transporter and monocarboxylate transporter 1. These transporters and other biotin-binding proteins partition biotin to compartments involved in biotin signaling: cytoplasm, mitochondria, and nuclei. The activity of cell signals such as biotinyl-AMP, Sp1 and Sp3, nuclear factor (NF)-kappaB, and receptor tyrosine kinases depends on biotin supply. Consistent with a role for biotin and its catabolites in ...
Biotin is an enzyme co-factor present in minute amounts in every living cell. Biotin is also known as coenzyme R and vitamin H or B7. It occurs mainly bound to proteins or polypeptides and is abundant in liver, kidney, pancreas, yeast, and milk. Biotin has been recognized as an essential nutrient. Humans fulfill their biotin requirement through their diet through endogenous reutilization of biotin and perhaps through the capture of biotin generated in the intestinal flora. The utilization of biotin for covalent attachment to carboxylases and its reutilization through the release of carboxylase biotin after proteolytic degradation constitutes the biotin cycle. Biotin deficiency is associated with neurological manifestations, skin rash, hair loss, and metabolic disturbances that are thought to relate to the various carboxylase deficiencies (metabolic ketoacidosis with lactic acidosis). It has also been suggested that biotin deficiency is associated with protein malnutrition, and that marginal biotin deficiency in pregnant women may be teratogenic. Biotin acts as a carboxyl carrier in carboxylation reactions. There are four biotin-dependent carboxylases in mammals: those of propionyl-CoA (PCC), 3-methylcrotonyl-CoA (MCC), pyruvate (PC), and acetyl-CoA carboxylases (isoforms ACC-1 and ACC-2). All but ACC-2 are mitochondrial enzymes. The biotin moiety is covalently bound to the epsilon amino group of a lysine residue in each of these carboxylases in a domain 60-80 amino acids long. The domain is structurally similar among carboxylases from bacteria to mammals. Evidence is emerging that biotin participates in processes other than classical carboxylation reactions. Specifically, novel roles for biotin in cell signalling, gene expression, and chromatin structure have been identified in recent years. Human cells accumulate biotin by using both the sodium-dependent multivitamin transporter and monocarboxylate transporter 1. These transporters and other biotin-binding proteins partition biotin to compartments involved in biotin signalling: cytoplasm, mitochondria, and nuclei. The activity of cell signals such as biotinyl-AMP, Sp1 and Sp3, nuclear factor (NF)-kappaB, and receptor tyrosine kinases depends on biotin supply. Consistent with a role for biotin and its catabolites in modulating these cell signals, greater than 2000 biotin-dependent genes have been identified in various human tissues. Many biotin-dependent gene products play roles in signal transduction and localize to the cell nucleus, consistent with a role for biotin in cell signalling. Posttranscriptional events related to ribosomal activity and protein folding may further contribute to the effects of biotin on gene expression. Finally, research has shown that biotinidase and holocarboxylase synthetase mediate covalent binding of biotin to histones (DNA-binding proteins), affecting chromatin structure; at least seven biotinylation sites have been identified in human histones. Biotinylation of histones appears to play a role in cell proliferation, gene silencing, and the cellular response to DNA repair. Roles for biotin in cell signalling and chromatin structure are consistent with the notion that biotin has a unique significance in cell biology (PMID: 15992684, 16011464).
Present in many foods; particularly rich sources include yeast, eggs, liver, certain fish (e.g. mackerel, salmon, sardines), soybeans, cauliflower and cow peas. Dietary supplement. Isolated from various higher plant sources, e.g. sweet corn seedlings and radish leaves
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.

[Raw Data] CB004_Biotin_pos_50eV_CB000006.txt
[Raw Data] CB004_Biotin_pos_30eV_CB000006.txt
[Raw Data] CB004_Biotin_pos_40eV_CB000006.txt
[Raw Data] CB004_Biotin_pos_20eV_CB000006.txt
[Raw Data] CB004_Biotin_pos_10eV_CB000006.txt
[Raw Data] CB004_Biotin_neg_10eV_000006.txt
[Raw Data] CB004_Biotin_neg_20eV_000006.txt

Biosynthesis
Biotin, synthesized in plants, is essential to plant growth and development.[22] Bacteria also synthesize biotin,[23] and it is thought that bacteria resident in the large intestine may synthesize biotin that is absorbed and utilized by the host organism.[18]

Biosynthesis starts from two precursors, alanine and pimeloyl-CoA. These form 7-keto-8-aminopelargonic acid (KAPA). KAPA is transported from plant peroxisomes to mitochondria where it is converted to 7,8-diaminopelargonic acid (DAPA) with the help of the enzyme, BioA. The enzyme dethiobiotin synthetase catalyzes the formation of the ureido ring via a DAPA carbamate activated with ATP, creating dethiobiotin with the help of the enzyme, BioD, which is then converted into biotin which is catalyzed by BioB.[24] The last step is catalyzed by biotin synthase, a radical SAM enzyme. The sulfur is donated by an unusual [2Fe-2S] ferredoxin.[25] Depending on the species of bacteria, Biotin can be synthesized via multiple pathways.[24]
Biotin (Vitamin B7) is a water-soluble B vitamin and serves as a coenzyme for five carboxylases in humans, involved in the synthesis of fatty acids, isoleucine, and valine, and in gluconeogenesis. Biotin is necessary for cell growth, the production of fatty acids, and the metabolism of fats and amino acids[1][2][3].
Biotin, vitamin B7 and serves as a coenzyme for five carboxylases in humans, involved in the synthesis of fatty acids, isoleucine, and valine, and in gluconeogenesis. Biotin is necessary for cell growth, the production of fatty acids, and the metabolism of fats and amino acids[1][2][3].
Biotin (Vitamin B7) is a water-soluble B vitamin and serves as a coenzyme for five carboxylases in humans, involved in the synthesis of fatty acids, isoleucine, and valine, and in gluconeogenesis. Biotin is necessary for cell growth, the production of fatty acids, and the metabolism of fats and amino acids[1][2][3].

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