CobamidesPentosyltransferases: Enzymes of the transferase class that catalyze the transfer of a pentose group from one compound to another.Nucleotidyltransferases: A class of enzymes that transfers nucleotidyl residues. EC 2.7.7.Nicotinamide-Nucleotide Adenylyltransferase: An enzyme that catalyzes reversibly the transfer of the adenylyl moiety of ATP to the phosphoryl group of NMN to form NAD+ and pyrophosphate. The enzyme is found predominantly in the nuclei and catalyzes the final reaction in the major pathway for the biosynthesis of NAD in mammals. EC 2.7.7.1.Veillonellaceae: A family of gram-negative bacteria, in the phylum FIRMICUTES.Nicotinamide Mononucleotide: 3-Carbamoyl-1-beta-D-ribofuranosyl pyridinium hydroxide-5'phosphate, inner salt. A nucleotide in which the nitrogenous base, nicotinamide, is in beta-N-glycosidic linkage with the C-1 position of D-ribose. Synonyms: Nicotinamide Ribonucleotide; NMN.Benzimidazoles: Compounds with a BENZENE fused to IMIDAZOLES.Salmonella enterica: A subgenus of Salmonella containing several medically important serotypes. The habitat for the majority of strains is warm-blooded animals.Methoprene: Juvenile hormone analog and insect growth regulator used to control insects by disrupting metamorphosis. Has been effective in controlling mosquito larvae.Vitamin B 12: A cobalt-containing coordination compound produced by intestinal micro-organisms and found also in soil and water. Higher plants do not concentrate vitamin B 12 from the soil and so are a poor source of the substance as compared with animal tissues. INTRINSIC FACTOR is important for the assimilation of vitamin B 12.Salmonella typhimurium: A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.Colitis, Ischemic: Inflammation of the COLON due to colonic ISCHEMIA resulting from alterations in systemic circulation or local vasculature.Galaxies: Large aggregates of CELESTIAL STARS; COSMIC DUST; and gas. (From McGraw Hill Dictionary of Scientific and Technical Terms, 6th ed)Spherocytes: Small, abnormal spherical red blood cells with more than the normal amount of hemoglobin.Crohn Disease: A chronic transmural inflammation that may involve any part of the DIGESTIVE TRACT from MOUTH to ANUS, mostly found in the ILEUM, the CECUM, and the COLON. In Crohn disease, the inflammation, extending through the intestinal wall from the MUCOSA to the serosa, is characteristically asymmetric and segmental. Epithelioid GRANULOMAS may be seen in some patients.Gastroenterology: A subspecialty of internal medicine concerned with the study of the physiology and diseases of the digestive system and related structures (esophagus, liver, gallbladder, and pancreas).Colitis: Inflammation of the COLON section of the large intestine (INTESTINE, LARGE), usually with symptoms such as DIARRHEA (often with blood and mucus), ABDOMINAL PAIN, and FEVER.Inflammatory Bowel Diseases: Chronic, non-specific inflammation of the GASTROINTESTINAL TRACT. Etiology may be genetic or environmental. This term includes CROHN DISEASE and ULCERATIVE COLITIS.Colitis, Ulcerative: Inflammation of the COLON that is predominantly confined to the MUCOSA. Its major symptoms include DIARRHEA, rectal BLEEDING, the passage of MUCUS, and ABDOMINAL PAIN.Physician-Patient Relations: The interactions between physician and patient.Halobacteriales: An order of extremely halophilic archaea, in the kingdom EURYARCHAEOTA. They occur ubiquitously in nature where the salt concentration is high, and are chemoorganotrophic, using amino acids or carbohydrates as a carbon source.Archaea: One of the three domains of life (the others being BACTERIA and Eukarya), formerly called Archaebacteria under the taxon Bacteria, but now considered separate and distinct. They are characterized by: (1) the presence of characteristic tRNAs and ribosomal RNAs; (2) the absence of peptidoglycan cell walls; (3) the presence of ether-linked lipids built from branched-chain subunits; and (4) their occurrence in unusual habitats. While archaea resemble bacteria in morphology and genomic organization, they resemble eukarya in their method of genomic replication. The domain contains at least four kingdoms: CRENARCHAEOTA; EURYARCHAEOTA; NANOARCHAEOTA; and KORARCHAEOTA.Haloferax volcanii: A species of halophilic archaea found in the Dead Sea.Haloferax: A genus of extremely halophilic HALOBACTERIACEAE which are chemoheterotropic and strictly aerobic. They are found in neutral saline environments such as salt lakes (especially the Dead Sea) and marine salterns.Halobacteriaceae: A family of extremely halophilic archaea found in environments with high salt concentrations, such as salt lakes, evaporated brines, or salted fish. Halobacteriaceae are either obligate aerobes or facultative anaerobes and are divided into at least twenty-six genera including: HALOARCULA; HALOBACTERIUM; HALOCOCCUS; HALOFERAX; HALORUBRUM; NATRONOBACTERIUM; and NATRONOCOCCUS.Haloferax mediterranei: A species of halophilic archaea found in the Mediterranean Sea. It produces bacteriocins active against a range of other halobacteria.DNA, Archaeal: Deoxyribonucleic acid that makes up the genetic material of archaea.Salinity: Degree of saltiness, which is largely the OSMOLAR CONCENTRATION of SODIUM CHLORIDE plus any other SALTS present. It is an ecological factor of considerable importance, influencing the types of organisms that live in an ENVIRONMENT.Gene Expression Regulation, Archaeal: Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in archaea.Sodium Chloride: A ubiquitous sodium salt that is commonly used to season food.Prenatal Nutritional Physiological Phenomena: Nutrition of FEMALE during PREGNANCY.Nurse Midwives: Professional nurses who have received postgraduate training in midwifery.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Rh-Hr Blood-Group System: Erythrocyte isoantigens of the Rh (Rhesus) blood group system, the most complex of all human blood groups. The major antigen Rh or D is the most common cause of erythroblastosis fetalis.ArchivesErythroblastosis, Fetal: A condition characterized by the abnormal presence of ERYTHROBLASTS in the circulation of the FETUS or NEWBORNS. It is a disorder due to BLOOD GROUP INCOMPATIBILITY, such as the maternal alloimmunization by fetal antigen RH FACTORS leading to HEMOLYSIS of ERYTHROCYTES, hemolytic anemia (ANEMIA, HEMOLYTIC), general edema (HYDROPS FETALIS), and SEVERE JAUNDICE IN NEWBORN.Rh Isoimmunization: The process by which fetal Rh+ erythrocytes enter the circulation of an Rh- mother, causing her to produce IMMUNOGLOBULIN G antibodies, which can cross the placenta and destroy the erythrocytes of Rh+ fetuses. Rh isoimmunization can also be caused by BLOOD TRANSFUSION with mismatched blood.Blood Group Incompatibility: An antigenic mismatch between donor and recipient blood. Antibodies present in the recipient's serum may be directed against antigens in the donor product. Such a mismatch may result in a transfusion reaction in which, for example, donor blood is hemolyzed. (From Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984).Animal Nutrition Sciences: The study of NUTRITION PROCESSES, as well as the components of food, their actions, interaction, and balance in relation to health and disease in animals.Fetomaternal Transfusion: Transplacental passage of fetal blood into the circulation of the maternal organism. (Dorland, 27th ed)Identity Crisis: Chaotic concept of self wherein one's role in life appears to be an insoluble dilemma often expressed by isolation, withdrawal, rebellion and extremism.Multiple Sclerosis: An autoimmune disorder mainly affecting young adults and characterized by destruction of myelin in the central nervous system. Pathologic findings include multiple sharply demarcated areas of demyelination throughout the white matter of the central nervous system. Clinical manifestations include visual loss, extra-ocular movement disorders, paresthesias, loss of sensation, weakness, dysarthria, spasticity, ataxia, and bladder dysfunction. The usual pattern is one of recurrent attacks followed by partial recovery (see MULTIPLE SCLEROSIS, RELAPSING-REMITTING), but acute fulminating and chronic progressive forms (see MULTIPLE SCLEROSIS, CHRONIC PROGRESSIVE) also occur. (Adams et al., Principles of Neurology, 6th ed, p903)Diarrhea: An increased liquidity or decreased consistency of FECES, such as running stool. Fecal consistency is related to the ratio of water-holding capacity of insoluble solids to total water, rather than the amount of water present. Diarrhea is not hyperdefecation or increased fecal weight.Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Weight Loss: Decrease in existing BODY WEIGHT.Multiple Sclerosis, Relapsing-Remitting: The most common clinical variant of MULTIPLE SCLEROSIS, characterized by recurrent acute exacerbations of neurologic dysfunction followed by partial or complete recovery. Common clinical manifestations include loss of visual (see OPTIC NEURITIS), motor, sensory, or bladder function. Acute episodes of demyelination may occur at any site in the central nervous system, and commonly involve the optic nerves, spinal cord, brain stem, and cerebellum. (Adams et al., Principles of Neurology, 6th ed, pp903-914)Antibiotic Prophylaxis: Use of antibiotics before, during, or after a diagnostic, therapeutic, or surgical procedure to prevent infectious complications.Feces: Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.Multiple Sclerosis, Chronic Progressive: A form of multiple sclerosis characterized by a progressive deterioration in neurologic function which is in contrast to the more typical relapsing remitting form. If the clinical course is free of distinct remissions, it is referred to as primary progressive multiple sclerosis. When the progressive decline is punctuated by acute exacerbations, it is referred to as progressive relapsing multiple sclerosis. The term secondary progressive multiple sclerosis is used when relapsing remitting multiple sclerosis evolves into the chronic progressive form. (From Ann Neurol 1994;36 Suppl:S73-S79; Adams et al., Principles of Neurology, 6th ed, pp903-914)Methylmalonic Acid: A malonic acid derivative which is a vital intermediate in the metabolism of fat and protein. Abnormalities in methylmalonic acid metabolism lead to methylmalonic aciduria. This metabolic disease is attributed to a block in the enzymatic conversion of methylmalonyl CoA to succinyl CoA.Folic Acid: A member of the vitamin B family that stimulates the hematopoietic system. It is present in the liver and kidney and is found in mushrooms, spinach, yeast, green leaves, and grasses (POACEAE). Folic acid is used in the treatment and prevention of folate deficiencies and megaloblastic anemia.Homocysteine: A thiol-containing amino acid formed by a demethylation of METHIONINE.Vitamin B 12 Deficiency: A nutritional condition produced by a deficiency of VITAMIN B 12 in the diet, characterized by megaloblastic anemia. Since vitamin B 12 is not present in plants, humans have obtained their supply from animal products, from multivitamin supplements in the form of pills, and as additives to food preparations. A wide variety of neuropsychiatric abnormalities is also seen in vitamin B 12 deficiency and appears to be due to an undefined defect involving myelin synthesis. (From Cecil Textbook of Medicine, 19th ed, p848)Diet, Vegetarian: Dietary practice of completely avoiding meat products in the DIET, consuming VEGETABLES, CEREALS, and NUTS. Some vegetarian diets called lacto-ovo also include milk and egg products.MalonatesMethylmalonyl-CoA Mutase: An enzyme that catalyzes the conversion of methylmalonyl-CoA to succinyl-CoA by transfer of the carbonyl group. It requires a cobamide coenzyme. A block in this enzymatic conversion leads to the metabolic disease, methylmalonic aciduria. EC 5.4.99.2.Transcobalamins: A group of carrier proteins which bind with VITAMIN B12 in the BLOOD and aid in its transport. Transcobalamin I migrates electrophoretically as a beta-globulin, while transcobalamins II and III migrate as alpha-globulins.CreatinineSpirulina: A genus of filamentous CYANOBACTERIA found in most lakes and ponds. It has been used as a nutritional supplement particularly due to its high protein content.Exercise Movement Techniques: Methods or programs of physical activities which can be used to promote, maintain, or restore the physical and physiological well-being of an individual.Seaweed: Multicellular marine macroalgae including some members of red (RHODOPHYTA), green (CHLOROPHYTA), and brown (PHAEOPHYTA) algae. They are widely distributed in the ocean, occurring from the tide level to considerable depths, free-floating (planktonic) or anchored to the substratum (benthic). They lack a specialized vascular system but take up fluids, nutrients, and gases directly from the water. They contain CHLOROPHYLL and are photosynthetic, but some also contain other light-absorbing pigments. Many are of economic importance as FOOD, fertilizer, AGAR, potash, or source of IODINE.Proton Pump Inhibitors: Compounds that inhibit H(+)-K(+)-EXCHANGING ATPASE. They are used as ANTI-ULCER AGENTS and sometimes in place of HISTAMINE H2 ANTAGONISTS for GASTROESOPHAGEAL REFLUX.Yogurt: A slightly acid milk food produced by fermentation due to the combined action of Lactobacillus acidophilus and Streptococcus thermophilus.Vitamin B 6: VITAMIN B 6 refers to several PICOLINES (especially PYRIDOXINE; PYRIDOXAL; & PYRIDOXAMINE) that are efficiently converted by the body to PYRIDOXAL PHOSPHATE which is a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, and aminolevulinic acid. During transamination of amino acids, pyridoxal phosphate is transiently converted into PYRIDOXAMINE phosphate. Although pyridoxine and Vitamin B 6 are still frequently used as synonyms, especially by medical researchers, this practice is erroneous and sometimes misleading (EE Snell; Ann NY Acad Sci, vol 585 pg 1, 1990). Most of vitamin B6 is eventually degraded to PYRIDOXIC ACID and excreted in the urine.Vitamin A: Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of CAROTENOIDS found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products.Corrinoids: Cyclic TETRAPYRROLES based on the corrin skeleton.SwitzerlandAlbumins: Water-soluble proteins found in egg whites, blood, lymph, and other tissues and fluids. They coagulate upon heating.Drug Carriers: Forms to which substances are incorporated to improve the delivery and the effectiveness of drugs. Drug carriers are used in drug-delivery systems such as the controlled-release technology to prolong in vivo drug actions, decrease drug metabolism, and reduce drug toxicity. Carriers are also used in designs to increase the effectiveness of drug delivery to the target sites of pharmacological actions. Liposomes, albumin microspheres, soluble synthetic polymers, DNA complexes, protein-drug conjugates, and carrier erythrocytes among others have been employed as biodegradable drug carriers.Vitamins: Organic substances that are required in small amounts for maintenance and growth, but which cannot be manufactured by the human body.Vitamin D: A vitamin that includes both CHOLECALCIFEROLS and ERGOCALCIFEROLS, which have the common effect of preventing or curing RICKETS in animals. It can also be viewed as a hormone since it can be formed in SKIN by action of ULTRAVIOLET RAYS upon the precursors, 7-dehydrocholesterol and ERGOSTEROL, and acts on VITAMIN D RECEPTORS to regulate CALCIUM in opposition to PARATHYROID HORMONE.Hypothyroidism: A syndrome that results from abnormally low secretion of THYROID HORMONES from the THYROID GLAND, leading to a decrease in BASAL METABOLIC RATE. In its most severe form, there is accumulation of MUCOPOLYSACCHARIDES in the SKIN and EDEMA, known as MYXEDEMA.Thyroid Gland: A highly vascularized endocrine gland consisting of two lobes joined by a thin band of tissue with one lobe on each side of the TRACHEA. It secretes THYROID HORMONES from the follicular cells and CALCITONIN from the parafollicular cells thereby regulating METABOLISM and CALCIUM level in blood, respectively.ran GTP-Binding Protein: A monomeric GTP-binding protein involved in nucleocytoplasmic transport of proteins into the nucleus and RNA into the cytoplasm. This enzyme was formerly listed as EC 3.6.1.47.Congenital Hypothyroidism: A condition in infancy or early childhood due to an in-utero deficiency of THYROID HORMONES that can be caused by genetic or environmental factors, such as thyroid dysgenesis or HYPOTHYROIDISM in infants of mothers treated with THIOURACIL during pregnancy. Endemic cretinism is the result of iodine deficiency. Clinical symptoms include severe MENTAL RETARDATION, impaired skeletal development, short stature, and MYXEDEMA.Thyroid Neoplasms: Tumors or cancer of the THYROID GLAND.Thyroid Hormones: Natural hormones secreted by the THYROID GLAND, such as THYROXINE, and their synthetic analogs.Thyroid Diseases: Pathological processes involving the THYROID GLAND.Thyroxine: The major hormone derived from the thyroid gland. Thyroxine is synthesized via the iodination of tyrosines (MONOIODOTYROSINE) and the coupling of iodotyrosines (DIIODOTYROSINE) in the THYROGLOBULIN. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form TRIIODOTHYRONINE which exerts a broad spectrum of stimulatory effects on cell metabolism.Thyrotropin: A glycoprotein hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Thyrotropin stimulates THYROID GLAND by increasing the iodide transport, synthesis and release of thyroid hormones (THYROXINE and TRIIODOTHYRONINE). Thyrotropin consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the pituitary glycoprotein hormones (TSH; LUTEINIZING HORMONE and FSH), but the beta subunit is unique and confers its biological specificity.Thyroid Function Tests: Blood tests used to evaluate the functioning of the thyroid gland.Dermatitis Herpetiformis: Rare, chronic, papulo-vesicular disease characterized by an intensely pruritic eruption consisting of various combinations of symmetrical, erythematous, papular, vesicular, or bullous lesions. The disease is strongly associated with the presence of HLA-B8 and HLA-DR3 antigens. A variety of different autoantibodies has been detected in small numbers in patients with dermatitis herpetiformis.Epidermolysis Bullosa: Group of genetically determined disorders characterized by the blistering of skin and mucosae. There are four major forms: acquired, simple, junctional, and dystrophic. Each of the latter three has several varieties.Pemphigus: Group of chronic blistering diseases characterized histologically by ACANTHOLYSIS and blister formation within the EPIDERMIS.Endoscopy, Gastrointestinal: Endoscopic examination, therapy or surgery of the gastrointestinal tract.Pemphigoid, Bullous: A chronic and relatively benign subepidermal blistering disease usually of the elderly and without histopathologic acantholysis.Epidermolysis Bullosa Dystrophica: Form of epidermolysis bullosa characterized by atrophy of blistered areas, severe scarring, and nail changes. It is most often present at birth or in early infancy and occurs in both autosomal dominant and recessive forms. All forms of dystrophic epidermolysis bullosa result from mutations in COLLAGEN TYPE VII, a major component fibrils of BASEMENT MEMBRANE and EPIDERMIS.Epidermolysis Bullosa, Junctional: Form of epidermolysis bullosa having onset at birth or during the neonatal period and transmitted through autosomal recessive inheritance. It is characterized by generalized blister formation, extensive denudation, and separation and cleavage of the basal cell plasma membranes from the basement membrane.Skin Diseases, Vesiculobullous: Skin diseases characterized by local or general distributions of blisters. They are classified according to the site and mode of blister formation. Lesions can appear spontaneously or be precipitated by infection, trauma, or sunlight. Etiologies include immunologic and genetic factors. (From Scientific American Medicine, 1990)Basement Membrane: A darkly stained mat-like EXTRACELLULAR MATRIX (ECM) that separates cell layers, such as EPITHELIUM from ENDOTHELIUM or a layer of CONNECTIVE TISSUE. The ECM layer that supports an overlying EPITHELIUM or ENDOTHELIUM is called basal lamina. Basement membrane (BM) can be formed by the fusion of either two adjacent basal laminae or a basal lamina with an adjacent reticular lamina of connective tissue. BM, composed mainly of TYPE IV COLLAGEN; glycoprotein LAMININ; and PROTEOGLYCAN, provides barriers as well as channels between interacting cell layers.Epidermolysis Bullosa Simplex: A form of epidermolysis bullosa characterized by serous bullae that heal without scarring. Mutations in the genes that encode KERATIN-5 and KERATIN-14 have been associated with several subtypes of epidermolysis bullosa simplex.Iodine: A nonmetallic element of the halogen group that is represented by the atomic symbol I, atomic number 53, and atomic weight of 126.90. It is a nutritionally essential element, especially important in thyroid hormone synthesis. In solution, it has anti-infective properties and is used topically.beta Carotene: A carotenoid that is a precursor of VITAMIN A. It is administered to reduce the severity of photosensitivity reactions in patients with erythropoietic protoporphyria (PORPHYRIA, ERYTHROPOIETIC). (From Reynolds JEF(Ed): Martindale: The Extra Pharmacopoeia (electronic version). Micromedex, Inc, Engewood, CO, 1995.)Fertility: The capacity to conceive or to induce conception. It may refer to either the male or female.Diet: Regular course of eating and drinking adopted by a person or animal.Superstitions: A belief or practice which lacks adequate basis for proof; an embodiment of fear of the unknown, magic, and ignorance.Dietary Supplements: Products in capsule, tablet or liquid form that provide dietary ingredients, and that are intended to be taken by mouth to increase the intake of nutrients. Dietary supplements can include macronutrients, such as proteins, carbohydrates, and fats; and/or MICRONUTRIENTS, such as VITAMINS; MINERALS; and PHYTOCHEMICALS.Micronutrients: Essential dietary elements or organic compounds that are required in only small quantities for normal physiologic processes to occur.

Binding of Cob(II)alamin to the adenosylcobalamin-dependent ribonucleotide reductase from Lactobacillus leichmannii. Identification of dimethylbenzimidazole as the axial ligand. (1/283)

The ribonucleoside triphosphate reductase (RTPR) from Lactobacillus leichmannii catalyzes the reduction of nucleoside 5'-triphosphates to 2'-deoxynucleoside 5'-triphosphates and uses coenzyme B12, adenosylcobalamin (AdoCbl), as a cofactor. Use of a mechanism-based inhibitor, 2'-deoxy-2'-methylenecytidine 5'-triphosphate, and isotopically labeled RTPR and AdoCbl in conjunction with EPR spectroscopy has allowed identification of the lower axial ligand of cob(II)alamin when bound to RTPR. In common with the AdoCbl-dependent enzymes catalyzing irreversible heteroatom migrations and in contrast to the enzymes catalyzing reversible carbon skeleton rearrangements, the dimethylbenzimidazole moiety of the cofactor is not displaced by a protein histidine upon binding to RTPR.  (+info)

The reaction of the substrate analog 2-ketoglutarate with adenosylcobalamin-dependent glutamate mutase. (2/283)

Glutamate mutase is one of several adenosylcobalamin-dependent enzymes that catalyze unusual rearrangements that proceed through a mechanism involving free radical intermediates. The enzyme exhibits remarkable specificity, and so far no molecules other than L-glutamate and L-threo-3-methylaspartate have been found to be substrates. Here we describe the reaction of glutamate mutase with the substrate analog, 2-ketoglutarate. Binding of 2-ketoglutarate (or its hydrate) to the holoenzyme elicits a change in the UV-visible spectrum consistent with the formation of cob(II)alamin on the enzyme. 2-ketoglutarate undergoes rapid exchange of tritium between the 5'-position of the coenzyme and C-4 of 2-ketoglutarate, consistent with the formation of a 2-ketoglutaryl radical analogous to that formed with glutamate. Under aerobic conditions this leads to the slow inactivation of the enzyme, presumably through reaction of free radical species with oxygen. Despite the formation of a substrate-like radical, no rearrangement of 2-ketoglutarate to 3-methyloxalacetate could be detected. The results indicate that formation of the C-4 radical of 2-ketoglutarate is a facile process but that it does not undergo further reactions, suggesting that this may be a useful substrate analog with which to investigate the mechanism of coenzyme homolysis.  (+info)

Methanol:coenzyme M methyltransferase from Methanosarcina barkeri -- substitution of the corrinoid harbouring subunit MtaC by free cob(I)alamin. (3/283)

Methyl-coenzyme M formation from coenzyme M and methanol in Methanosarcina barkeri is catalysed by an enzyme system composed of three polypeptides MtaA, MtaB and MtaC, the latter of which harbours a corrinoid prosthetic group. We report here that MtaC can be substituted by free cob(I)alamin which is methylated with methanol in an MtaB-catalysed reaction and demethylated with coenzyme M in an MtaA-catalysed reaction. Methyl transfer from methanol to coenzyme M was found to proceed at a relatively high specific activity at micromolar concentrations of cob(I)alamin. This finding was surprising because the methylation of cob(I)alamin catalysed by MtaB alone and the demethylation of methylcob(III)alamin catalysed by MtaA alone exhibit apparent Km for cob(I)alamin and methylcob(III)alamin of above 1 mm. A possible explanation is that MtaA positively affects the MtaB catalytic efficiency and vice versa by decreasing the apparent Km for their corrinoid substrates. Activation of MtaA by MtaB was methanol-dependent. In the assay for methanol:coenzyme M methyltransferase activity cob(I)alamin could be substituted by cob(I)inamide which is devoid of the nucleotide loop. Substitution was, however, only possible when the assays were supplemented with imidazole: approximately 1 mm imidazole being required for half-maximal activity. Methylation of cob(I)inamide with methanol was found to be dependent on imidazole but not on the demethylation of methylcob(III)inamide with coenzyme M. The demethylation reaction was even inhibited by imidazole. The structure and catalytic mechanism of the MtaABC complex are compared with the cobalamin-dependent methionine synthase.  (+info)

Adenosylcobalamin-mediated methyl transfer by toluate cis-dihydrodiol dehydrogenase of the TOL plasmid pWW0. (4/283)

We identified and characterized a methyl transfer activity of the toluate cis-dihydrodiol (4-methyl-3,5-cyclohexadiene-cis-1, 2-diol-1-carboxylic acid) dehydrogenase of the TOL plasmid pWW0 towards toluene cis-dihydrodiol (3-methyl-4,5-cyclohexadiene-cis-1, 2-diol). When the purified enzyme from the recombinant Escherichia coli containing the xylL gene was incubated with toluene cis-dihydrodiol in the presence of NAD+, the end products differed depending on the presence of adenosylcobalamin (coenzyme B12). The enzyme yielded catechol in the presence of adenosylcobalamin, while it gave 3-methylcatechol in the absence of the cofactor. Adenosylcobalamin was transformed to methylcobalamin as a result of the enzyme reaction, which indicates that the methyl group of the substrate was transferred to adenosylcobalamin. Other derivatives of the cobalamin such as aquo (hydroxy)- and cyanocobalamin did not mediate the methyl transfer reaction. The dehydrogenation and methyl transfer reactions were assumed to occur concomitantly, and the methyl transfer reaction seemed to depend on the dehydrogenation. To our knowledge, the enzyme is the first dehydrogenase that shows a methyl transfer activity as well.  (+info)

Co-ordinate variations in methylmalonyl-CoA mutase and methionine synthase, and the cobalamin cofactors in human glioma cells during nitrous oxide exposure and the subsequent recovery phase. (5/283)

We investigated the co-ordinate variations of the two cobalamin (Cbl)-dependent enzymes, methionine synthase (MS) and methylmalonyl-CoA mutase (MCM), and measured the levels of their respective cofactors, methylcobalamin (CH3Cbl) and adenosylcobalamin (AdoCbl) in cultured human glioma cells during nitrous oxide exposure and during a subsequent recovery period of culture in a nitrous oxide-free atmosphere (air). In agreement with published data, MS as the primary target of nitrous oxide was inactivated rapidly (initial rate of 0.06 h(-1)), followed by reduction of CH3Cbl (to <20%). Both enzyme activity and cofactor levels recovered rapidly when the cells were subsequently cultured in air, but the recovery was completely blocked by the protein-synthesis inhibitor, cycloheximide. During MS inactivation, there was a reduction of cellular AdoCbl and holo-MCM activity (measured in the absence of exogenous AdoCbl) to about 50% of pre-treatment levels. When the cells were transferred to air, both AdoCbl and holo-MCM activity recovered, albeit more slowly than the MS system. Notably, the regain of the holo-MCM and AdoCbl was enhanced rather than inhibited by cycloheximide. These findings confirm irreversible damage of MS by nitrous oxide; hence, synthesis of the enzyme is required to restore its activity. In contrast, restoration of holo-MCM activity is only dependent on repletion of the AdoCbl cofactor. We also observed a synchronous fluctuation in AdoCbl and the much larger hydroxycobalamin pool during the inactivation and recovery phase, suggesting that the loss and repletion of AdoCbl reflect changes in intracellular Cbl homoeostasis. Our data demonstrate that the nitrous oxide-induced changes in MS and CH3Cbl are associated with reversible changes in both MCM holoactivity and the AdoCbl level, suggesting co-ordinate distribution of Cbl cofactors during depletion and repletion.  (+info)

Identification and expression of the genes encoding a reactivating factor for adenosylcobalamin-dependent glycerol dehydratase. (6/283)

Adenosylcobalamin-dependent glycerol dehydratase undergoes inactivation by glycerol, the physiological substrate, during catalysis. In permeabilized cells of Klebsiella pneumoniae, the inactivated enzyme is reactivated in the presence of ATP, Mg2+, and adenosylcobalamin. We identified the two open reading frames as the genes for a reactivating factor for glycerol dehydratase and designated them gdrA and gdrB. The reactivation of the inactivated glycerol dehydratase by the gene products was confirmed in permeabilized recombinant Escherichia coli cells coexpressing GdrA and GdrB proteins with glycerol dehydratase.  (+info)

Structure and dynamics of the B12-binding subunit of glutamate mutase from Clostridium cochlearium. (7/283)

Glutamate mutase (Glm) is an adenosylcobamide-dependent enzyme that catalyzes the reversible rearrangement of (2S)-glutamate to (2S, 3S)-3-methylaspartate. The active enzyme from Clostridium cochlearium consists of two subunits (of 53.6 and 14.8 kDa) as an alpha2beta2 tetramer, whose assembly is mediated by coenzyme B12. The smaller of the protein components, GlmS, has been suggested to be the B12-binding subunit. Here we report the solution structure of GlmS, determined from a heteronuclear NMR-study, and the analysis of important dynamical aspects of this apoenzyme subunit. The global fold and dynamic behavior of GlmS in solution are similar to those of the corresponding subunit MutS from C. tetanomorphum, which has previously been investigated using NMR-spectroscopy. Both solution structures of the two Glm B12-binding subunits share striking similarities with that determined by crystallography for the B12-binding domain of methylmalonyl CoA mutase (Mcm) from Propionibacterium shermanii, which is B12 bound. In the crystal structure a conserved histidine residue was found to be coordinated to cobalt, displacing the endogenous axial ligand of the cobamide. However, in GlmS and MutS the sequence motif, Asp-x-His-x-x-Gly, which includes the cobalt-coordinating histidine residue, and a predicted alpha-helical region following the motif, are present as an unstructured and highly mobile loop. In the absence of coenzyme, the B12-binding site apparently is only partially formed. By comparing the crystal structure of Mcm with the solution structures of B12-free GlmS and MutS, a consistent picture on the mechanism of B12 binding has been obtained. Important elements of the binding site only become structured upon binding B12; these include the cobalt-coordinating histidine residue, and an alpha helix that forms one side of the cleft accommodating the nucleotide 'tail' of the coenzyme.  (+info)

Isolation of acetate auxotrophs of the methane-producing archaeon Methanococcus maripaludis by random insertional mutagenesis. (8/283)

To learn more about autotrophic growth of methanococci, we isolated nine conditional mutants of Methanococcus maripaludis after transformation of the wild type with a random library in pMEB.2, a suicide plasmid bearing the puromycin-resistance cassette pac. These mutants grew poorly in mineral medium and required acetate or complex organic supplements such as yeast extract for normal growth. One mutant, JJ104, was a leaky acetate auxotroph. A plasmid, pWDK104, was recovered from this mutant by electroporation of a plasmid preparation into Escherichia coli. Transformation of wild-type M. maripaludis with pWDK104 produced JJ104-1, a mutant with the same phenotype as JJ104, thus establishing that insertion of pWDK104 into the genome was responsible for the phenotype. pWDK104 contained portions of the methanococcal genes encoding an ABC transporter closely related to MJ1367-MJ1368 of M. jannaschii. Because high levels of molybdate, tungstate, and selenite restored growth to wild-type levels, this transporter may be specific for these oxyanions. A second acetate auxotroph, JJ117, had an absolute growth requirement for either acetate or cobalamin, and wild-type growth was observed only in the presence of both. Cobinamide, 5', 6'-dimethylbenzimidazole, and 2-aminopropanol did not replace cobalamin. This phenotype was correlated with tandem insertions in the genome but not single insertions and appeared to have resulted from an indirect effect on cobamide metabolism. Plasmids rescued from other mutants contained portions of ORFs denoted in M. jannaschii as endoglucanase (MJ0555), transketolase (MJ0681), thiamine biosynthetic protein thiI (MJ0931), and several hypothetical proteins (MJ1031, MJ0835, and MJ0835.1).  (+info)

*Ribonucleoside-triphosphate reductase

Blakley, R.L. (1965). "Cobamides and ribonucleotide reduction. I. Cobamide stimulation of ribonucleotide reduction in extracts ...

*Nicotinate-nucleotide-dimethylbenzimidazole phosphoribosyltransferase

"Structural investigation of the biosynthesis of alternative lower ligands for cobamides by nicotinate mononucleotide: 5,6- ...

*List of MeSH codes (D03)

... cobamides MeSH D03.383.129.578.840.437.777.560 --- hydroxocobalamin MeSH D03.383.129.578.840.500 --- porphyrins MeSH D03.383. ... cobamides MeSH D03.549.909.437.777.560 --- hydroxocobalamin MeSH D03.549.909.500 --- porphyrins MeSH D03.549.909.500.250 --- ...

*List of MeSH codes (D04)

... cobamides MeSH D04.345.783.437.777.560 --- hydroxocobalamin MeSH D04.345.783.500 --- porphyrins MeSH D04.345.783.500.250 --- ...
TY - JOUR. T1 - Identification and expression of the genes encoding a reactivating factor for adenosylcobalamin-dependent glycerol dehydratase. AU - Tobimatsu, Takamasa. AU - Kajiura, Hideki. AU - Yunoki, Michio. AU - Azuma, Muneaki. AU - Toraya, Tetsuo. PY - 1999/7. Y1 - 1999/7. N2 - Adenosylcobalamin-dependent glycerol dehydratase undergoes inactivation by glycerol, the physiological substrate, during catalysis. In permeabilized cells of Klebsiella pneumoniae, the inactivated enzyme is reactivated in the presence of ATP, Mg2+, and adenosylcobalamin. We identified the two open reading frames as the genes for a reactivating factor for glycerol dehydratase and designated them gdrA and gdrB. The reactivation of the inactivated glycerol dehydratase by the gene products was confirmed in permeabilized recombinant Escherichia coli cells coexpressing GdrA and GdrB proteins with glycerol dehydratase.. AB - Adenosylcobalamin-dependent glycerol dehydratase undergoes inactivation by glycerol, the ...
1C9K: Three-dimensional structure of adenosylcobinamide kinase/adenosylcobinamide phosphate guanylyltransferase (CobU) complexed with GMP: evidence for a substrate-induced transferase active site.
1JHA: Structural investigation of the biosynthesis of alternative lower ligands for cobamides by nicotinate mononucleotide: 5,6-dimethylbenzimidazole phosphoribosyltransferase from Salmonella enterica.
B12 from vegetarian sources?. Some dieticians claim you can get B12 from plant sources, such as seaweed, fermented soy, spirulina and brewers yeast. In reality, these foods only contain analogs of B12 called "cobamides". Cobamides can block your intake of B12 and increase your need for the real thing. [4]. Why women need to supplement vitamin B12. We have seen how vitamin B-12 deficiency is especially common in vegans and vegetarians because typical vitamin B12 sources (meats, yoghurt, etc.) are simply not present in their diets.. But even meat eaters eating B12 foods several times a day may be deficient in B12 due to poor digestion, particularly older people who suffer a diminished ability to absorb nutrients in their small intestine.. Vitamin B12 can only be absorbed in the small intestine, and due to common intestinal ailments, absorption can be blocked. Vitamin B12 deficiency can be caused by low stomach acid and heavy alcohol use. Drugs like proton pump inhibitors (Prilosec and Nexium) ...
Looking for Coenzyme b12? Find out information about Coenzyme b12. see coenzyme coenzyme , any one of a group of relatively small organic molecules required for the catalytic function of certain enzymes. A coenzyme may... Explanation of Coenzyme b12
Allergy Research Group features B12 Adenosylcobalamin a highly absorbable form of vitamin B12. Vitamin B12 plays a role in brain and nervous system health. Also features folic...
I am considering the addition of adenosylcobalamin to my supplements. Which brand do you use? I want one without folic acid/folate added. Thanks!
Buy adenosyl capsule 10 capsules pack online at discounted price. visit 1mg.com to know price, benefits and product information of adenosyl capsule.
Vitamin B12 (as adenosylcobalamin and 50% hydroxycobalamin) 2,000 mcg Other Ingredients: Hypoallergenic plant fiber (cellulose, vegetarian capsule (cellulose, water) Warning: If pregnant, consult your physician before taking this or any other product. Keep out of reach of children. Tamper resistant, use only if safety seal is intact. Store sealed in a cool, dry place. ...
Description: Subject matter wherein the composition includes an agent which acts as a stabilizer for the active ingredient therein or acts to enhance the topical absorption thereof ...
EC 1.6.99.9; other name: vitamin B12r reductase; a flavoprotein enzyme that catalyses a reaction between NADH and two molecules of cob(ii)alamin to form two molecules of cob(i)alamin and NAD+. ...
The enzyme catalyzes the the conversion of precorrin-8X to hydrogenobyrinate by methyl rearrangement, a step in the aerobic (late cobalt insertion) pathway of adenosylcobalamin biosynthesis ...
MetabolismBiosynthesis of cofactors, prosthetic groups, and carriersHeme, porphyrin, and cobalamin5,6-dimethylbenzimidazole synthase (TIGR02476; EC 1.14.99.40; HMM-score: 20.4) ...
This enzyme catalyses the C-1 methylation of cobalt-precorrin-5B in the anaerobic (early cobalt insertion) pathway of adenosylcobalamin biosynthesis.
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ŞANDRU, S.; BALTAGA, R.; BELÎI, A.; COBÂLEŢCHI, S.; GUZUN, N.; ROJNOVEANU, Gh. Managementul anestezic la pacienţii cu traumă hepatică. În: Săndesc D., Bedreag O., Păpurică M. Recomandări şi protocoale în anestezie. Terapie intensivă şi medicină de urgenţă, Timişoara, 2012, p.169-181. ISBN 978-973-52-1260- ...
Vitamin B(12) (cobalamin, Cbl) is essential to the function of two human enzymes, methionine synthase (MS) and methylmalonyl-CoA mutase (MUT). The conversion of dietary Cbl to its cofactor forms, methyl-Cbl (MeCbl) for MS and adenosyl-Cbl (AdoCbl) for MUT, located in the cytosol and mitochondria, respectively, requires a complex pathway of intracellular processing and trafficking. One of the processing proteins, MMAA (methylmalonic aciduria type A), is implicated in the mitochondrial assembly of AdoCbl into MUT and is defective in children from the cblA complementation group of cobalamin disorders. To characterize the functional interplay between MMAA and MUT, we have crystallized human MMAA in the GDP-bound form and human MUT in the apo, holo, and substrate-bound ternary forms. Structures of both proteins reveal highly conserved domain architecture and catalytic machinery for ligand binding, yet they show substantially different dimeric assembly and interaction, compared with their bacterial
TY - JOUR. T1 - One pathway can incorporate either adenine or dimethylbenzimidazole as an α-axial ligand of B12 cofactors in Salmonella enterica. AU - Anderson, Peter J.. AU - Lango, Jozsef. AU - Carkeet, Colleen. AU - Britten, Audrey. AU - Kräutler, Bernhard. AU - Hammock, Bruce D.. AU - Roth, John R.. PY - 2008/2. Y1 - 2008/2. N2 - Corrinoid (vitamin B12-like) cofactors contain various α-axial ligands, including 5,6-dimethylbenzimidazole (DMB) or adenine. The bacterium Salmonella enterica produces the corrin ring only under anaerobic conditions, but it can form "complete" corrinoids aerobically by importing an "incomplete" corrinoid, such as cobinamide (Cbi), and adding appropriate α- and β-axial ligands. Under aerobic conditions, S. enterica performs the corrinoid-dependent degradation of ethanolamine if given vitamin B12, but it can make B12 from exogenous Cbi only if DMB is also provided. Mutants isolated for their ability to degrade ethanolamine without added DMB converted Cbi to ...
NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. PART I. Use of a mixture of non- and tetradeutero-beta-methylaspartate with coenzyme B12 dependent beta-methylaspartate-glutamate mutase has shown that the hydrogen that migrates becomes one of three equivalent hydrogens during the reaction. Kinetic isotope effects suggest that cleavage of the bond in the substrate from carbon to that hydrogen which migrates is an important component of the rate determining step. The evidence also supports the existence of an intermediate which can partition with similar probabilities to beta-methylaspartate or to glutamate. Some possible mechanistic implications of these findings are discussed. PART II. The mechanism and the kinetics of the action of diol dehydrase on 3-fluoro-1,2-propanediol, a new substrate for diol dehydrase, were examined. The results of this study lead to a reexamination of the kinetic behavior of the natural substrate, ...
We report on a combined experimental and theoretical study of the adsorption of the paramagnetic organic radical 2,2,5,5-tetramethyl-3-carboxypyrrolidine nitroxide (3-carboxyproxyl, 3CP) on a Cu(110) surface. Information from scanning tunneling microscopy (STM), reflection absorption infrared spectroscopy, and periodic density functional theory (DFT) calculations reveals important insights into the nature of the molecule-metal interface. We find that the molecule is robustly anchored to the surface via the formation of two Cu-O bonds between the carboxylate functionality and specific short-bridge adsorption sites on the Cu(110) surface. The adsorbed organic radicals appear in STM as discrete entities on the surface and can be imaged with submolecular resolution. We observe a tendency for local 2D ordering. Importantly, 3CP molecules adopt a preferred site, dictated by the strong interaction of the carboxylate groups and the steric repulsion of the methyl groups with the surface which orient the ...
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Methylcobalamin is the only form of vitamin B-12 found in the brain. The liver is unable to convert the common form of B-12, cyanocobalamin, into an ample supply of methylcobalamin. Sublingual Methylcobalamin supports a healthy brain and spinal cord.
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Vitamin B-12, a family of compounds called cobalamins, is one of eight essential B-complex vitamins. Foods or dietary supplements might contain several types of cobalamins, but your body converts dietary B-12 into two active forms -- methylcobalamin and 5-deoxyadenosyl cobalamin -- and uses these forms to maintain ...
Bluebonnet Earth Sweet Chewables Methylcobalamin Vitamin B12 delivers 1,000 mcg of methylcobalamin, a highly bioavailable form of vitamin B12. Known for its role in energy pro...
Biologically Active Form of B-12 The methylcobalamin form, available in this convenient chewable tablet, is the most active form of Vitamin B-12 and is shown to have advantages over cyanocobalamin...
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Active Coenzyme Form of Vitamin B-12 Methylcobalamin, an active coenzyme form of Vitamin B-12, is essential for cell growth and replication. It is more concentrated than other forms of B-12...
Buy Solgar Methylcobalamin 1000 g (Vitamin B12) Nuggets online. promotes the health of the circulatory and nervous systems and supports energy metabolism.
Do you think sublingual methylcobalamin, i.e. vitamin b12, will get into the bloodstream and have a local effect, if I apply it to my skin with DMSO?
Woodson, J.D. and Escalante-Semerena, J.C. (2004). "CbiZ, an amidohydrolase enzyme required for salvaging the coenzyme B12 precursor cobinamide in archaea". Proc. Natl. Acad. Sci. USA 101: 3591-3596. PMID 14990804. ...
methylcobalamin injections out of the three types available are the best form of B12 vitamins for various issues affecting the body.
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Cob is an ancient building material thats basically wet earth and straw mixed together and rolled into loaf-sized pieces or cobs. The mixture is very similar to clay, and what makes cob houses unique and beautiful is the organic shape. Instead of assembling and covering a frame, builders stack cobs, then use the same clay-like material to mold the walls by hand [source: Liloia]. The result is a structure with curving lines instead of sharp angles, and many cob structures include lots of fun, built-in features like shelves and hooks molded right into the walls. Some of these homes even feature built-in furniture, like couches and tables, molded from cob.. Because cob is made from natural materials, it has a very low environmental footprint compared to other building materials like concrete. Cob doesnt have to be made in a factory and shipped across the country [source: Liola]. And you can find mud and straw very close to the building site.. ...
HPDIs KIDS MIGHTY-MULTI! is truly one-of-a-kind. It is most similar to the Mighty Multi-Vite! in terms of the nutrients it provides, including antioxidants. However, it is our only chewable and it tastes great.. KIDS MIGHTY-MULTI! is an advanced chewable multivitamin for children incorporating the latest nutritional research in a tasty, complete formula combining the highest-quality and most usable forms of vitamins, minerals, herbs, and cofactors.. Our childrens multivitamin formula provides optimal levels of basic essential nutrients and thereby is an ideal foundation upon which to build a complete nutritional supplement program. A high-quality multivitamin is the starting-point for building a program uniquely designed to suit to your childs individual requirements.. We offer KIDS MIGHTY-MULTI! as a "top-of-the-line" childrens formula that tastes great and produces exceptional results. This unique formula very effectively provides children with a solid foundation of nutrients for ...
A derivative of arsenic acid by replacement of a hydroxyl group by an organic radical. * * * ar·son·ic ac·id (ahr sonґik) an organic compound containing the AsO(OH)2 functional group
Can you match the French Vegetables? Test your knowledge on this language quiz to see how you do and compare your score to others. Quiz by cob579cob
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B-12 is also known as cobalamin and methylcobalamin. It is so important for healthy central nervous system. It also helps support healthy metabolism. Will you get enough from your diet? Now with chewable maxi B-12 5000, you can be sure and you wont
Methylcobalamin is super important to health because its the form of vitamin B12 our bodies use. Lets make it easier to remember and say.
தேரா சச்சா அமைப்பைச் சேர்ந்த 400 பேர் ஆண்மையிழப்பு அறுவை சிகிச்சை செய்துகொண்ட வழக்கில், சி.பி.ஐ குர்மீத்திடம் நேற்று வாக்குமூலம் பெற்றது. CBI questions Ram Rahim on forced castration of his followers
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Lactobacillus leichmannii ATCC ® 7830D-5™ Designation: Genomic DNA from Lactobacillus leichmannii strain 313 TypeStrain=False Application: Assay of vitamin B12 cobalamin, cobalamins Food testing
Lactobacillus leichmannii ATCC ® 7830™ Designation: 313 TypeStrain=False Application: Assay of vitamin B12 cobalamin, cobalamins Food testing Pharmaceutical and Personal Care
In my practice I use different forms of Vitamin B12. In this article I explain some of the differences between cyanocobalamin, methylcobalamin, and hydroxocobalamin.. Cyanocobalamin can be given as an intramuscular injection. It should not be given intravenously. However, after injection it will need to convert to methylcobalamin, and then to hydroxocobalamin to be used by the body. Of all the forms of Vitamin B12 it is the least painful for the patient to inject. After introduction into the body it provides a small amount of cyanide. For individuals who are overall very healthy this is a good choice and this is also the least expensive form of injectable Vitamin B12. It is known that some people, such as smokers, are less able to transform cyanocobalamin into methylcobalamin due to toxins and heavy metals in the liver. These individuals need to use other forms of Vitamin B12.. Methylcobalamin is more bioactive and can be given intramuscularly, intravenously, and intraarticularly. It is slightly ...
Methylcobalamin Liquid provides 1,000 mcg of highly bioavailable vitamin B12 in a tasty and convenient liquid. Vitamin B12 is important in numerous essential body.. Methylcobalamin Injection. Blood conditions. B12 deficient and am trying to find some methylcobalamin to buy over the.Methylcobalamin Liquid Methyl-Guard Methyl-Guard Plus Mg-Zyme Millivital Mn-Zyme Multi-Gland Multi-Mins. Vitamin B12 Methylcobalamin sublingual Vitamin C w/ Flavonoids.Methylcobalamin - die natürliche Form von Vitamin B12 Methylcobalamin-Kapseln Sehr gutes Preis-Leistungs-Verhältnis (0,25 € pro 1000 µg Methylcobalamin ...
SUGGESTED USAGE: As a dietary supplement, take 1 tablet 1-2 times daily. BENEFITS: B Complex Vitamins are needed by the body for energy production, synthesis of hormones and blood cells, healthy nervous system function, and numerous other metabolic processes. The forms of the B Vitamins found in foods and most supplements, however, are not readily utilized by the body. They require conversion into their active forms before they can perform their functions as cofactors in biochemical reactions CoEnzyme B Complex contains B Vitamins already in their active or Coenzyme forms. This enables the body to use them more quickly and efficiently because, once absorbed, they are transported directly to their site of action, requiring no conversion. CoEnzyme B Complex tablets are enteric coated to enhance bioavailability and delivery to intestinal absorption sites intact, unharmed by stomach acids.* Supplement Facts Serving Size: 2 Tablets
The enteric bacterium Salmonella typhimurium synthesizes cobalamin (vitamin B12) de novo only under anaerobic growth conditions. We initiated a genetic analysis of the cobalamin biosynthetic (cob) gene cluster, Stable cob::lac operon fusions were generated by insertions of a transposition-defective derivative of bacteriophage Mu d1 (Ap lac) into the cob genes. beta-Galactosidase synthesis was repressed in the presence of exogenously supplied cyanocobalamin, demonstrating that the cobalamin biosynthetic pathway was regulated by end-product repression. Transcriptional polarity studies showed that the cob genes responsible for synthesis of the corrinoid intermediate cobinamide (branch I of the pathway) were organized into a single operon. Genes for the synthesis of 5,6-dimethylbenzimidazole (branch II) and the final assembly of the complete cobalamin molecule (branch III) were organized into two or more additional operons. All of the known cob genes (in branches I, II, and III) were transcribed in ...
The present invention is directed to a method of preparing an organic-alkali metal-boron salt of the formula:wherein Z is an alkali metal selected from the group consisting of lithium and sodium, wherein B is boron, wherein Ar is an aromatic organic radical selected from a specified group of radicals, wherein R is an organic radical selected from methyl and ethyl, wherein Ar is an aromatic organic radical selected from the group consisting of specified divalent dicyclic radicals, wherein m is a numerical value such that 0.ltoreq.m.ltoreq.4, wherein n is a numerical value such that 0.ltoreq.n.ltoreq.2, and wherein x is a numerical value such that 0.ltoreq.x.ltoreq.2, subject to the provisio that the sum of m and n and x is such that the total valence of the organic radicals Ar, R and Ar equals four. The method involves the reaction of a nitrogen-containing compound of the formula:wherein Q is selected from the group consisting of specified nitrogen
b>Methylcobalamin - Cherry Flavored Sublingual. Description May Play A Role In Normal Nerve Function. Methylcobalamin, an active coenzyme form of vitamin B-12, is essential for cell growth and replication. It is more concentrated than other forms of B-12 in the cerebral spinal fluid, where it can be used by the central nervous system. It donates methyl groups to the myelin sheath that insulates certain nerve fibers. It may also play a role in maintaining a healthy sleep-wake cycle, as well as normal nerve function. Supplement Facts Serving Size: 1 Tablet Servings per container: 60 Amount Per Serving % Daily Value Vitamin B12 (as methylcobalamin) 5 mg 83,330% Other ingredients: Mannitol, sorbitol, stearic acid, natural cherry flavor, and magnesium stearate. Free Of No added yeast, dairy, egg, gluten, soy or wheat. Contains no salt, preservatives, or artificial color, flavor or fragrance. Suitable for vegetarians. Directions As a dietary supplement, take 1 tablet
A 1973 study suggests that once absorbed, MeCbl may be retained in the body better than CNCbl (1).. A 2011 clinical trial from Korea found that 1,500 µg/day of MeCbl was effective at raising vitamin B12 levels, reducing or eliminating neurological symptoms of B12 deficiency, and lowering homocysteine levels (5). This trial was done on people who had a gastrectomy and, therefore, had vitamin B12 malabsorption, indicating that for most people 1,500 µg/day would be more than enough. There was no comparison group receiving CNCbl.. I am unaware of any clinical trials testing the various forms of vitamin B12 against each other among the general population and most people seem to do well using CNCbl.. Some people with chronic fatigue report getting more relief from AdoCbl than either MeCbl or CNCbl (more info), while other people report feeling better only when taking both AdoCbl and MeCbl. Its possible this could be a real effect, but could also be due to a placebo effect or taking more B12 and ...
p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.,/p> ,p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.,/p> ,p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).,/p> ,p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x,sup>64,/sup> + x,sup>4,/sup> + x,sup>3,/sup> + x + 1. The algorithm is described in the ISO 3309 standard. ,/p> ,p class="publication">Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.,br /> ,strong>Cyclic redundancy and other checksums,/strong>,br /> ,a href="http://www.nrbook.com/b/bookcpdf.php">Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993),/a>),/p> Checksum:i ...
Notice the use of methylcobalamin ("Me-B12") both to lower homocysteine and to increase the serum B12 level. Dr. Bredesen is getting results in preventing and reversing dementia, and hes using methylcobalamin as part of his treatment strategy. Why would I use a form of B12 that is tightly bound together, i.e., cyanocobalamin, when methylcobalamin appears to help prevent dementia ...
Methylcobalamin is vitamin B12 prescribed to treat peripheral neuropathy, diabetic neuropathy. It is essential for normal nerve function, maintains a healthy sleep-wake cycle.
Having a sterically exposed half-filled orbital, bonding with the substrate occurs together with an inner-sphere single electron transfer from a single nickel center resulting in reduction of unsaturated molecules (C2H4 and CO2) and homolytic cleavage of various σ-bonds including those in the following molecules: H-H, H2N-NH2 and H3C-CN.. Angew. Chem., Int. Ed. 2017, 56, 9502-9506.. DOI: 10.1002/anie.201704487. ...
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|p|Provides 1 mg (16,670% of DV) of Methylcobalamin B-12|/p| |p|B-12 is essential for healthy red blood cells, energy levels, and DNA production and plays an important role in maintaining normal nerve function. It is often lacking in a vegan diet because
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Id need a lot more than that to give my boys shots. Id either have to be told I have to, or there would need to be overwhelming evidence to support it. Neither happened for me (thankfully) and I found easier ways to help my boys.
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dpdk-test-report] ,SUCCESS, pw61572-61577 [PATCH] [v8, 1/6] bus/fslmc: fix the conflicting dmb function @ 2019-10-21 13:00 dpdklab 0 siblings, 0 replies; 3+ messages in thread From: dpdklab @ 2019-10-21 13:00 UTC (permalink / raw) To: Ali Alnubani, Test Report; +Cc: dpdk-test-reports [-- Attachment #1: Type: text/plain, Size: 3905 bytes --] Test-Label: iol-mellanox-Performance Test-Status: SUCCESS http://dpdk.org/patch/61572 _Performance Testing PASS_ Submitter: Gavin Hu ,[email protected], Date: Monday, October 21 2019 09:47:54 DPDK git baseline: Repo:dpdk Branch: master CommitID:b36f587f010bba421a8fd0b4c383276ecb796ae3 61572-61577 --, performance testing pass Test environment and result as below: Ubuntu 18.04 Kernel: 4.15.0-generic GCC: 7.4 NIC: Mellanox ConnectX-5 100000 Mbps Target: x86_64-native-linuxapp-gcc Fail/Total: 0/6 Detail performance results: +------------+---------+-------------------------------------+ , frame_size , txd/rxd , throughput difference from expected , ...
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Mutations in the human MMAA gene cause the metabolic disorder cblA-type methylmalonic aciduria (MMA), although knowledge of the mechanism of dysfunction remains lacking. MMAA regulates the incorporation of the cofactor adenosylcobalamin (AdoCbl), generated from the MMAB adenosyltransferase, into the destination enzyme methylmalonyl-CoA mutase (MUT). This function of MMAA depends on its GTPase activity, which is stimulated by an interaction with MUT. Here, we present 67 new patients with cblA-type MMA, identifying 19 novel mutations. We biochemically investigated how missense mutations in MMAA in 22 patients lead to disease. About a third confer instability to the recombinant protein in bacterial and human expression systems. All 15 purified mutant proteins demonstrated wild-type like intrinsic GTPase activity and only one (p.Asp292Val), where the mutation is in the GTP binding domain, revealed decreased GTP binding. However, all mutations strongly decreased functional association with MUT by ...
Nucleoside analogues of 5-deoxy-5-adenosylcobalamin have been synthesized by reduction of cyanocobalamin with zinc in ammonium chloride, followed by reaction with the 5-chloro derivatives of inosine, thioinosine (6-mercaptopurine riboside), adenine arabinoside, cytosine arabinoside, 2-fluoroadenosine, homoadenosine, 1,N6-ethenoadenosine, tubercidin, and formycin. These analogues, several alkylcobalamins (CH3-, CCl2F-, CClF2, aminoethyl-, and carboxypentyl-), and adenosyl- and methylcobinamide were tested as inhibitors of the adenosylcobalamin-dependent ribonucleotide reductase (EC 1.17.4.2) from Lactobacillus leichmannii. The fluoroadenosine derivative had full coenzymatic activity (Km = 6.7 x 10-7 M), but all the other cobalamin analogues were inhibitory; most effective were the formycin (Ki, = 1.0 x 10-6 M) and adenine arabinoside (Ki = 3.0 x 10-6 M) analogues. The cobinamides were very weak inhibitors. When tested as inhibitors of the transcobalamin II-mediated transport of vitamin B12 ...
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Synonyms for cyanocobalamin in Free Thesaurus. Antonyms for cyanocobalamin. 3 synonyms for cyanocobalamin: antipernicious anemia factor, cobalamin, vitamin B12. What are synonyms for cyanocobalamin?
The total synthesis of the complex biomolecule vitamin B12 was first accomplished by the collaborating research groups of Robert Burns Woodward at Harvard and Albert Eschenmoser at ETH in 1972. It is considered a classic in the field of total synthesis of natural products. Work on the synthesis started 1960 at ETH, and in 1961 at Harvard, it was collaboratively pursued after 1965, and required the effort of no less than 91 post-doctoral fellows (mostly at Harvard) and 12 Ph.D. students (at ETH) from 19 different nations. There are two variants of this synthesis, concomitantly accomplished in 1972. These two syntheses are intricately intertwined chemically, yet they basically differ in their overall strategy of creating the macrocyclic corrin ligand system of the vitamin molecule. The variant collaboratively pursued and finished at Harvard closes the macrocyclic corrin ring between rings A and B (the "A/B variant"), while the synthesis accomplished at ETH achieves the corrin ring closure between ...
Bartl, Joerg; Steenken, S.; Mayr, Herbert und McClelland, R. A. (1990): Photo-heterolysis and -homolysis of substituted diphenylmethyl halides, acetates, and phenyl ethers in acetonitrile: characterization of diphenylmethyl cations and radicals generated by 248-nm laser flash photolysis. In: Journal of the American Chemical Society, Vol. 112, Nr. 19: S. 6918-6928 ...
The peculiar form of the corrin ring with the direct link between rings A and D and the position of the methyl group at C-24 make the two sides of the corrin ring system very stereochemically and the differences are reinforced by the positions of the methyl group and acetamide and propionamide residues attached at the carbon atoms (cf.. Nobel Lecture The X-Ray Analysis Of Complicated Molecules. ...
Buy Discount CLEARANCE - Vitamin B12 Methylcobalamin, 90 Tablets, Natural Factors (Exp. 02/17) at VitaSprings. Find more product information on Vitamin B12 Methylcobalamin and shop online.
Quaternary ammonium compounds are any of a group of ammonium salts in which organic radicals have been substituted for all four hydrogens of the original ammonium cation. They has a central nitrogen atom which is joined to four organic radicals and one acid radical. The organic radicals may be alkyl, aryl, or aralkyl, and the nitrogen can be part of a ring system. They are prepared by treatment of an amine with an alkylating agent. They show a variety of physical, chemical, and biological properties and most compounds are soluble in water and strong electrolytes. Such compounds include ...
Cyanocobalamin - Is it really true that cyanocobalamin can be used as a sex stimulus? Only if it is low. Cyanocobalamin is also known as vitamin b12. While it can boost energy in some people, generally, if it is not low to begin with, it will likely have little effect.
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The three forms of B12 found in Tricobalamin™ can be readily converted to the active intracellular forms of B12, such as methylcobalamin, adenosylcobalamin, glutathionylcobalamin, and possibly other physiologically active B12 forms. Tricobalamin™ uses a l
Looking for online definition of CBI in the Medical Dictionary? CBI explanation free. What is CBI? Meaning of CBI medical term. What does CBI mean?
Coby Slager is a professional photographer based in New Plymouth, Taranaki. Coby is passionate about photography and loves every aspect of photography from, "Capturing the Moment" to enhancing all photos into fine prints. Photography is all about the essence of who and what you are and as such, a photograph is much more than a likeliness on a piece of paper. A photograph tells a story of a moment in time that subsequently can be relived again and again. Photography is about real people, real relationships and real emotions, this is what a makes good photograph priceless.. Photo shoots can take place in Cobys studio, in or around your home or at a location of you choice. It goes without saying that the main focus is on the end product.. At Coby Slager Photography I believe that the journey to get there must be a good one too. I want you to have a good time whilst we create these wonderful images. This means I will do anything in my power to help you relax and enjoy the process and if that means ...
Looking for online definition of gets a cob on in the Medical Dictionary? gets a cob on explanation free. What is gets a cob on? Meaning of gets a cob on medical term. What does gets a cob on mean?
Looking for CBI? Find out information about CBI. in agriculture, artificial watering of the land. Although used chiefly in regions with annual rainfall of less than 20 in. , it is also used in wetter areas... Explanation of CBI
a class of organic compounds of nitrogen that may be considered as derived from ammonia (NH3) by replacing one or more of the hydrogen atoms by organic radicals, such as CH3 or C6H5, as in methylamine and aniline. The former is a gas at ordinary temperature and pressure, but other amines are liquids or solids. All amines are basic in nature and usually combine readily with hydrochloric or other strong acids to form salts ...
Miffed by the Central Bureau of Investigation for not informing him of its decision to close the murder case of thirteen-year-old Aarushi Talwar, her father Rajesh Talwar said, We had pinned our hopes on the investigation but it has been shattered.Rajesh said, Claiming the CBI had not properly verified Aarushis DNA and other forensic reports, he said he would meet CBI Director AP Singh over the issue.We had done everything to get our daughter justice, he said. | Aarushis parents blame CBI for shoddy probe
Vitamin B12 is one of the most important daily nutrients a person can get. Problem is, most people are not getting adequate amounts of it. And even when they are, people aren t absorbing enough B12. Pure Advantage has an answer. Pure Advantage s B12 spray is a cut above other B12 products because it is available in the methylcobalamin form. Methylcobalamin is the most absorbable form of B12. This is extremely important when taking supplemental B12, especially for vegetarians. Because B12 is found mainly in meat sources, vegetarians are often deficient in this important daily vitamin ...
This option is a MUST for those with mutations at the MTHFR gene. This is also recommended for vegetarians, vegans, the elderly, and anyone else with low levels of B12. When looking for B12 supplements in the store, be sure to look for it in the form of methylcobalamin instead of cyanocobalamin. Methyl-B12 is the best form for the body to utilize and will have the greatest impact on your B12 levels ...
Objective : The contribution ofpolymorphism of DMA and DMB alleles to the pathogenesis of Japanese RA was studied. The association of DM alleles with HLA-DRB1*0405 and *0802, which were positively and negatively susceptible to Japanese RA, respectively, is also discussed. Methods : DMA and DMB typing was carried out in 91 Japanese RA patients...
FDA pregnancy category C. It is not known whether this medication can harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. Cyanocobalamin passes into breast milk, but it is not known whether cyanocobalamin could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby ...
The Delhi High Court on Wednesday granted two months more time to the Central Bureau of Investigation (CBI) to probe alleged bribery charges against agencys former Special Director Rakesh Asthana and its officer Devendra Kumar. Justice Vibhu Bakhru while granting more time to the agency said: It
Business lobbying organisation, CBI, has spoken out over the lack of women on exec boards, launching a call for action for all listed companies to measure progress of getting female employees to ...
I know this is probably not the right thread but anyway, Im new to Children Of Bodom, and so I ask, What does COBHC mean, I know COB means Children O...
Im afraid Ive got COB syndrome. Camera-on-the-brain. Ever get that? Its not love, and I dont think it quite ranks as infatuation, either. Maybe its akin to infatuation with a star-someone youll never meet and who wouldnt particularly want to...
MetabolismBiosynthesis of cofactors, prosthetic groups, and carriersHeme, porphyrin, and cobalamincobyrinic acid a,c-diamide synthase (TIGR00379; EC 6.3.1.-; HMM-score: 19) ...
Two cousins, aged 14 and 15, went missing last Tuesday and were allegedly gang-raped and murdered. The next day, their bodies were found hanging from a tree. 5 main accused held, 2 absconding
Signed-off-by: Nikolay Sivov ,nsivov at codeweavers.com, --- dlls/dmband/tests/dmband.c , 4 ++-- dlls/dmcompos/tests/dmcompos.c , 8 ++++---- dlls/dmime/tests/dmime.c , 10 +++++----- dlls/dmime/tests/performance.c , 2 +- dlls/dmloader/tests/loader.c , 4 ++-- dlls/dmstyle/tests/dmstyle.c , 6 +++--- dlls/dmsynth/tests/dmsynth.c , 4 ++-- dlls/dmusic/tests/dmusic.c , 4 ++-- 8 files changed, 21 insertions(+), 21 deletions(-) diff --git a/dlls/dmband/tests/dmband.c b/dlls/dmband/tests/dmband.c index e1f00ae701..f3042ea3e2 100644 --- a/dlls/dmband/tests/dmband.c +++ b/dlls/dmband/tests/dmband.c @@ -55,7 +55,7 @@ static void test_COM(void) HRESULT hr; /* COM aggregation */ - hr = CoCreateInstance(&CLSID_DirectMusicBand, (IUnknown*)&dmb, CLSCTX_INPROC_SERVER, + hr = CoCreateInstance(&CLSID_DirectMusicBand, (IUnknown *)0xdeadbeef, CLSCTX_INPROC_SERVER, &IID_IUnknown, (void**)&dmb); ok(hr == CLASS_E_NOAGGREGATION, DirectMusicBand create failed: %08x, expected CLASS_E_NOAGGREGATION\n, hr); @@ -104,7 +104,7 ...
Cyanocobalamin (commonly known as Vitamin B12) is the most chemically complex of all the vitamins. Cyanocobalamins structure is based on a corrin ring, which, although similar to the porphyrin ring found in heme, chlorophyll, and cytochrome, has two of the pyrrole rings directly bonded. The central metal ion is Co (cobalt). Cyanocobalamin cannot be made by plants or by animals, as the only type of organisms that have the enzymes required for the synthesis of cyanocobalamin are bacteria and archaea. Higher plants do not concentrate cyanocobalamin from the soil and so are a poor source of the substance as compared with animal tissues. Cyanocobalamin is naturally found in foods including meat (especially liver and shellfish), eggs, and milk products. [HMDB]
Corrinoids from various ovine tissue samples (liver, blood, small intestinal fluid and faeces) were analysed using a combination of high-performance liquid chromatography (HPLC) and a radioisotope dilution assay (RIDA) to estimate the distribution of corrinoids - the cobalamins hydroxocobalamin (OH-cbl), methylcobalamin (me-cbl) and 5-deoxyadenosylcobalamin (ado-cbl), and cobalamin analogues - in these tissues. Samples were taken from either cobalt-deficient or cobalt-replete ewes, and ruminant and pre-ruminant lambs. In liver, ado-cbl predominated, followed by analogues, OH-cbl and me-cbl. Supplementation with either cobalt (ruminant) or vitamin B12 injections (pre-ruminant) increased the amount of ado-cbl and decreased analogues. In blood, OH-cbl predominated, followed by ado-cbl, analogues and me-cbl, respectively. In small intestinal fluid, the distribution from largest to smallest percentage was analogues, ado-cbl, OH-cbl and me-cbl. In faeces, analogues constituted the greatest proportion,
Emeritus Chief of Gastroenterology Dr. Lawrence J. Brandts research interests include ischemic and vascular disorders of the gastrointestinal system, inflammatory bowel diseases, C. difficile colitis, geriatric gastroenterology, AIDS, and endoscopic technique. Long-standing major interests are the patient-doctor relationship and the way that a patients psychological makeup influences his/her illnesses and treatments.. Amongst his contributions are: the performance of the first non-operative gastric polypectomy; the demonstration that gastrointestinal bacteria produce cobamides from dietary vitamin B12 that may inhibit vitamin B12 absorption; that metronidazole can heal and maintain healing of perineal Crohns disease; that most cases of newly diagnosed IBD in the elderly are actually ischemic colitis misdiagnosed as ulcerative or Crohns colitis; the classification of ischemic colitis and description of its natural history according to site of colonic involvement; the first demonstration of ...
Another common mechanism that is covered in the first weeks of organic chemistry is the free radical halogenation of alkanes. This mechanism utilizes the homolytic cleavage (one electron per atom) property of halogens when exposed to heat or ionizing radiation (i.e. hv), which is a popular mechanism for future reactions in the course. Radical halogens can extract the proton from a C-H bond to produce the corresponding acid and generate a radical carbon center. In this article we will discuss all of the tips and tricks to getting an A on your racical halogenation questions. Sign up with StudyOrgo today for more in-depth mechanism coverage and answers to all of your organic chemistry questions!. Generating a radical halogen: there are THREE critical steps to free radical reactions.. 1) Initiation: The Br2 single bond is broken by high energy ligh (hv) to form radicals placing one electron on each atom.. ...
In agreement with previous studies,1, 6 we found an almost 50% decline in the concentration of cobalamins during late pregnancy (Table 1). A small increase in MMA was observed during pregnancy and post partum (Table 1) but we question whether this is caused by an increased metabolic rate during pregnancy and lactation rather than a sign of vitamin B12 deficiency. Only two women (holoTC: 33-43 pmol/L and 39-48 pmol/L) had a MMA above the upper limit of the reference intervals (,0.28 μmol/L) at all four time points during pregnancy and post partum. None of the women had a MMA ,0.75 μmol/L, the diagnostic level for vitamin B12 deficiency,7 at any time during pregnancy and post partum. These results suggest that the vitamin B12 status during pregnancy remains unchanged and that a sufficient amount of cobalamin was available for transportation into the cells despite the decreased level of total plasma cobalamins.. Interestingly, the decline in cobalamins during pregnancy was not reflected in holoTC ...
TY - JOUR. T1 - Early-onset combined methylmalonic aciduria and homocystinuria. T2 - Neuroradiologic findings. AU - Rossi, A.. AU - Cerone, R.. AU - Biancheri, R.. AU - Gatti, R.. AU - Schiaffino, M. C.. AU - Fonda, C.. AU - Zammarchi, E.. AU - Tortori-Donati, P.. PY - 2001. Y1 - 2001. N2 - BACKGROUND AND PURPOSE: Combined methylmalonic aciduria and homocystinuria (MMA-HC) is caused by impaired hepatic conversion of dietary cobalamin to methylcobalamin and adenosylcobalamin, resulting in decreased activity of methylmalonyl-CoA mutase and methionine synthase. Patients with the early-onset variety present within 12 months of age with severe neurologic, hematologic, and gastrointestinal abnormalities. We describe the neuroradiologic features of early-onset MMA-HC and discuss related pathophysiological mechanisms. METHODS: Twelve infants with hypotonia, failure to thrive, poor feeding, and hematologic abnormalities were diagnosed with MMA-HC on the basis of a typical plasmatic and urinary metabolic ...
Cobalamin is a complex organic molecule containing a tetrapyrole corrin ring that is similar in structure to heme but that has a divalent cobalt atom in its center instead of an iron atom. Like heme iron, this cobalt atom binds to two ligands. One is a benzimidazole nucleotide, whereas the other can be either a methyl group (found in methylcobalamin) or an adenosyl group (found in adenosylcobalamin). Cobalamin is present in all foods of animal origin including meat, fish, and dairy products. Food cobalamin is tightly bound to proteins. Following ingestion, some cobalamin in food is transferred to human haptocorrin in saliva. As depicted in Figure 6-1, the low pH of the gastric juice facilitates efficient release and transfer of the remaining food cobalamin to haptocorrin. After transit to the duodenum, the increase in pH enables the transfer of cobalamin from haptocorrin to intrinsic factor, a transport protein secreted by gastric parietal cells. The cobalamin-intrinsic factor complex resists ...
Kinetic studies were performed on the superoxide dismutases isolated from the anaerobic bacterium Propionibacterium shermanii as active enzymes with either iron or manganese, which were naturally incorporated into the same molecule depending on the metal supply. Both the Fe- and Mn- forms showed decreasing activity with increasing pH. This suggests the protonation of some groups near the metal, possibly a metal-bound water molecule. Thus the kinetic behaviour of this superoxide dismutase is much more dependent on the protein structure than on the metal incorporated into the active site. The secondary structures of both forms were not influenced by variations in pH, whereas the EPR spectra of the Fe-superoxide dismutase changed as a function of pH. The EPR spectra apparently consist of two overlapping species. Steady-state experiments proved that all iron-containing species show catalytic activity, but the species predominating in the alkaline pH range displays a lower reaction rate. The ...

RCSB PDB 









- 1JHA: Structural Investigation of the Biosynthesis of Alternative Lower Ligands for Cobamides by...RCSB PDB - 1JHA: Structural Investigation of the Biosynthesis of Alternative Lower Ligands for Cobamides by...

Structural investigation of the biosynthesis of alternative lower ligands for cobamides by nicotinate mononucleotide: 5,6- ... Structural Investigation of the Biosynthesis of Alternative Lower Ligands for Cobamides by Nicotinate Mononucleotide:5,6- ...
more infohttp://www.rcsb.org/pdb/explore/explore.do?structureId=1JHA

RCSB PDB 









- 1JH8: Structural Investigation of the Biosynthesis of Alternative Lower Ligands for Cobamides by...RCSB PDB - 1JH8: Structural Investigation of the Biosynthesis of Alternative Lower Ligands for Cobamides by...

Structural investigation of the biosynthesis of alternative lower ligands for cobamides by nicotinate mononucleotide: 5,6- ... Structural Investigation of the Biosynthesis of Alternative Lower Ligands for Cobamides by Nicotinate Mononucleotide:5,6- ...
more infohttp://www.rcsb.org/pdb/explore/litView.do?structureId=1JH8

Ribonucleoside-triphosphate reductase - WikipediaRibonucleoside-triphosphate reductase - Wikipedia

Blakley, R.L. (1965). "Cobamides and ribonucleotide reduction. I. Cobamide stimulation of ribonucleotide reduction in extracts ...
more infohttps://en.wikipedia.org/wiki/Ribonucleoside-triphosphate_reductase

Research Brief 276: Novel Cobamide Structure May Hold Clues for More Effective Biological Degradation of Chlorinated Compounds ...Research Brief 276: Novel Cobamide Structure May Hold Clues for More Effective Biological Degradation of Chlorinated Compounds ...

A majority of organisms, including humans, require cobamides for normal functioning. Vitamin B12 is the best-known member of ... Enzymes that depend on cobamides fulfill essential metabolic functions in most organisms, including mammals. As a result, a ... The researchers previously discovered that changes to the lower base structure of cobamides influence the bioremediation ... Understanding the biological and geochemical conditions that support the production of specific cobamides, which efficiently ...
more infohttps://tools.niehs.nih.gov/srp/researchbriefs/view.cfm?Brief_ID=276

Production of Vitamin B12 Analogues in Patients with Small-Bowel Bacterial Overgrowth | Annals of Internal Medicine | American...Production of Vitamin B12 Analogues in Patients with Small-Bowel Bacterial Overgrowth | Annals of Internal Medicine | American...

Cobamides ([AdeJCNCba, [2-Me Ade] CNCba, [CN]2Cbi and factor E) were found in the intestinal contents in three of the four ... Thus bacterial production of cobamides, both de novo and from ingested CN-Cbl bound to intrinsic factor, occurs in humans with ... We investigated the presence of vitamin B12 analogues (cobamides) and the bacterial conversion of 57Co-B12 (vitamin B12 ... Radioactivity of cobamide zones from duplicate chromatograms showed bacterial conversion of (57Co)-CN-Cbl into cobamides. ...
more infohttp://annals.org/aim/article-abstract/691540/production-vitamin-b12-analogues-patients-small-bowel-bacterial-overgrowth

Brandt Steps Down as GI Chief | Einstein/Montefiore Department of Medicine | Albert Einstein College of MedicineBrandt Steps Down as GI Chief | Einstein/Montefiore Department of Medicine | Albert Einstein College of Medicine

... the demonstration that gastrointestinal bacteria produce cobamides from dietary vitamin B12 that may inhibit vitamin B12 ...
more infohttp://www.einstein.yu.edu/departments/medicine/medicine.aspx?id=24145

2-17-2011: Medicine Grand Rounds | Einstein/Montefiore Department of Medicine | Albert Einstein College of Medicine2-17-2011: Medicine Grand Rounds | Einstein/Montefiore Department of Medicine | Albert Einstein College of Medicine

... the demonstration that gastrointestinal bacteria produce cobamides from dietary vitamin B12 that may inhibit vitamin B12 ...
more infohttp://www.einstein.yu.edu/departments/medicine/medicine.aspx?id=28816

Northwestern University - Research Output
     - Northwestern ScholarsNorthwestern University - Research Output - Northwestern Scholars

Battocletti, J. H., Linehan, J. H., Larson, S. J., Sances, A., Bowman, R. L., Kudravcev, V., Genthe, W. K., Halbach, R. E. & Evans, S. M., Jan 1 1972, In : IEEE Transactions on Biomedical Engineering. BME-19, 6, p. 403-407 5 p.. Research output: Contribution to journal › Letter ...
more infohttps://www.scholars.northwestern.edu/en/organisations/northwestern-university/publications/?type=%2Fdk%2Fatira%2Fpure%2Fresearchoutput%2Fresearchoutputtypes%2Fcontributiontojournal%2Fletter&page=12%E2%88%A8dering=title&descending=false

Metabolism of halophilic archaea | SpringerLinkMetabolism of halophilic archaea | SpringerLink

Halobacterium assimilates corrinoid precursors and cobamides through a high-affinity transport system, but is also able to ... that cobamides are synthesized under aerobic conditions in Halobacterium (Woodson et al. 2003). Haloarchaeal genomes encode ...
more infohttps://link.springer.com/article/10.1007%2Fs00792-008-0138-x

The Good Ol Grignard  |  In the PipelineThe Good Ol' Grignard | In the Pipeline

Co-C bond of the cobamides (vitamin B12 et al) come to mind as being pretty stable, especially in cyanocobalamin ...
more infohttps://blogs.sciencemag.org/pipeline/archives/2020/02/06/the-good-ol-grignard

Are You Getting Adequate Amounts of This Bone Healthy Vitamin?Are You Getting Adequate Amounts of This Bone Healthy Vitamin?

Its a process that is subject to disruption and blockage, such as interruptions caused by cobamides. Cobamides are substances ...
more infohttps://saveourbones.com/are-you-getting-adequate-amounts-of-this-bone-healthy-vitamin/

Nicotinate-nucleotide-dimethylbenzimidazole phosphoribosyltransferase - WikipediaNicotinate-nucleotide-dimethylbenzimidazole phosphoribosyltransferase - Wikipedia

"Structural investigation of the biosynthesis of alternative lower ligands for cobamides by nicotinate mononucleotide: 5,6- ...
more infohttps://en.wikipedia.org/wiki/Nicotinate-nucleotide%E2%80%94dimethylbenzimidazole_phosphoribosyltransferase

Prenatal Nutrition - from Ronnie Falcãos Midwife
      ArchivesPrenatal Nutrition - from Ronnie Falcão's Midwife Archives

But plant foods said to contain B12 actually contain B12 analogs called cobamides that block intake of and increase the need ...
more infohttps://www.gentlebirth.org/archives/nutrition.html

Vitamin B12 Deficiency: What It Is, Symptoms & Treatment | Chris KresserVitamin B12 Deficiency: What It Is, Symptoms & Treatment | Chris Kresser

However, plant foods said to contain B12 actually contain B12 analogs called cobamides that block the intake of and increase ...
more infohttps://chriskresser.com/b12-deficiency-a-silent-epidemic-with-serious-consequences/

The Wheldon Protocol, Some Advice, Please... - This Is MS Multiple Sclerosis Knowledge & Support CommunityThe Wheldon Protocol, Some Advice, Please... - This Is MS Multiple Sclerosis Knowledge & Support Community

But plant foods said to contain B12 actually contain B12 analogs called cobamides that block intake of and increase the need ...
more infohttps://www.thisisms.com/forum/viewtopic.php?p=223897

Post Punk Kitchen Forum • View topic - B-12 best way to get itPost Punk Kitchen Forum • View topic - B-12 best way to get it

But plant foods said to contain B12 actually contain B12 analogs called cobamides that block intake of and increase the need ...
more infohttp://forum.theppk.com/viewtopic.php?p=578501

Vitamin and Amino Acid Auxotrophy in Anaerobic Consortia Operating under Methanogenic Conditions | mSystemsVitamin and Amino Acid Auxotrophy in Anaerobic Consortia Operating under Methanogenic Conditions | mSystems

Growth inhibition of Sporomusa ovata by incorporation of benzimidazole bases into cobamides. J Bacteriol 195:1902-1911. doi: ...
more infohttp://msystems.asm.org/content/2/5/e00038-17

6 Keys to a Healthy Plant-Based Diet | John Douillards LifeSpa6 Keys to a Healthy Plant-Based Diet | John Douillard's LifeSpa

They found these B12 sources contain B12 analogs called cobamides, which may block the absorption of the bodys bio-available ...
more infohttp://lifespa.com/6-keys-healthy-plant-based-diet/

Why sufficient vitamin B12 is ESSENTIAL for women | Pilates FitnessWhy sufficient vitamin B12 is ESSENTIAL for women | Pilates Fitness

In reality, these foods only contain analogs of B12 called "cobamides". Cobamides can block your intake of B12 and increase ...
more infohttp://pilatesfitness.co.uk/blog/?p=242

Syntheses and characterization of vitamin B12-Pt(II) conjugates and their adenosylation in an enzymatic assay  - Zurich Open...Syntheses and characterization of vitamin B12-Pt(II) conjugates and their adenosylation in an enzymatic assay - Zurich Open...

Despite bearing a rather large metal complex on the beta-axial position, the cobamides in 5 and 7 are recognized by the ... Despite bearing a rather large metal complex on the beta-axial position, the cobamides in 5 and 7 are recognized by the ...
more infohttp://www.zora.uzh.ch/id/eprint/14352/

High-throughput structural biology of metabolic enzymes and its impact on human diseases. - Nuffield Department of Orthopaedics...High-throughput structural biology of metabolic enzymes and its impact on human diseases. - Nuffield Department of Orthopaedics...

Humans, Disease, Cobamides, Enzymes, Signal Transduction, Protein Conformation, Metabolism, Mutation, Models, Molecular, Drug ...
more infohttps://www.ndorms.ox.ac.uk/publications/166729

18 years on T4...and feeling rubbish - Thyroid UK | HealthUnlocked18 years on T4...and feeling rubbish - Thyroid UK | HealthUnlocked

These analogues (cobamides) can interfere with absorption of true vitamin B12 and disrupt B12 metabolism. Those who choose not ...
more infohttps://healthunlocked.com/thyroiduk/posts/135327343/18-years-on-t4...and-feeling-rubbish

NYSGE - New York Society for Gastrointestinal EndoscopyNYSGE - New York Society for Gastrointestinal Endoscopy

the demonstration that gastrointestinal bacteria produce cobamides from dietary vitamin B12 that may inhibit vitamin B12 ...
more infohttp://www.nysge.org/content.asp?contentid=51

Click to printClick to print

BUT: Those contain B12 analogs called cobamides that block the intake of, and increase the need for, true B12. Read more here ...
more infohttps://www.metabolance.com/why-i-no-longer-support-veganism-part-1-nutrition/
  • We investigated the presence of vitamin B12 analogues (cobamides) and the bacterial conversion of 57 Co-B12 (vitamin B12 cyanocobalamin, [ 57 Co]-CN-Cbl) into cobamides in the intestinal contents of four patients with bacterial overgrowth. (annals.org)
  • Thus bacterial production of cobamides, both de novo and from ingested CN-Cbl bound to intrinsic factor, occurs in humans with bacterial overgrowth states and results in a significant loss of vitamin B12 to the host. (annals.org)