| nicotinamide riboside kinase | <enzyme> Phosphorylates 3-deazaguanosine and tiazofurin Registry number: EC 2.7.1.- (26 Jun 1999) |
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| nicotinamide-nucleotide adenylyltransferase | <enzyme> An enzyme that catalyses 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 catalyses the final reaction in the major pathway for the biosynthesis of NAD in mammals. Chemical name: ATP:nicotinamide-nucleotide adenylyltransferase Registry number: EC 2.7.7.1 (12 Dec 1998) |
| nicotinate | Salt or ester of nicotinic acid; some nicotinate's are used in ointments as rubefacients. (05 Mar 2000) |
| nicotinatenucleotide-dimethylbenzimidazole phosphoribosyltransferase | <enzyme> Involved in the synthesis of adenosyl-cobalamin (coenzyme b12); amino acid sequence given in second source Registry number: EC 2.4.2.21 Synonym: nicotinate ribonucleotide benzimidazole phosphoribosyltransferase, trans-n-glycosidase, nicotinate-nucleotide-dimethylbenzimidazole phosphoribosyltransferase, cobu gene product, cobt protein, scobt protein, cobt gene product (26 Jun 1999) |
| nicotine | <drug> A plant alkaloid from tobacco, blocks transmission at nicotinic synapses. (18 Nov 1997) |
| nicotine dehydrogenase | <enzyme> Mo-pterin-fe-s cluster- and fad-dependent enzyme composed of 3 unequal polypeptides; catalyses the conversion of nicotine, acceptor, and water to (s)-6-hydroxynicotine and reduced acceptor Registry number: EC 1.5.99.4 (26 Jun 1999) |
| nicotine oxidase | <enzyme> Cytochrome p-450 enzyme Registry number: EC 1.5.3.- (26 Jun 1999) |
| nicotine stomatitis | Heat stimulated lesions, usually on the palate, that begin with erythema and progress to multiple white papules with a red dot in the centre. The red dot represents a dilated, inflamed salivary duct orifice. (05 Mar 2000) |
| nicotinehydroxamic acid methiodide | An effective cholinesterase reactivator, with actions that are most marked at the skeletal neuromuscular junction; antidotal effects are less striking at autonomic effector sites, and insignificant in the central nervous system. (05 Mar 2000) |
| nicotinic | <chemistry> Pertaining to, or derived from, nicotine; nicotic; used specifically to designate an acid related to pyridine, obtained by the oxidation of nicotine, and called nicotinic acid. Source: Websters Dictionary (01 Mar 1998) |
| nicotinic acetylcholine receptor | Integral membrane protein of the postsynaptic membrane to which acetylcholine binds. The receptor contains an integral ion channel, as a result of binding of acetylcholine, ion channels in the subsynaptic membrane are opened. at the neuromuscular junction, the nicotinic acetylcholine receptor initiates muscle contraction. Currently the best characterised ion channel protein: made of a hetero pentamer of related subunits, although a homo pentamer is functional in insects. Structural studies show that the acetylcholine binding site and the ionic channel are part of the same macromolecular unit. The nAChR mediates rapid transduction events (1ms) whereas receptors activating G-protein coupled channels operate on slower time scales (millisecond to second range). (18 Nov 1997) |
| nicotinic acid | A precursor of NAD, that is a product of the oxidation of nicotine. (18 Nov 1997) |
| nicotinic acid amide | <biochemistry> Member of the water soluble B vitamin group, used in the production of fatty acids, steroids and cholesterol, deficiency is known as pellagra. Has cholesterol-lowering and vasodilating properties. (27 Sep 1997) |
| nicotinic acid maculopathy | Maculopathy observed in persons taking 3000 mg or more of nicotinic acid daily; normal vision returns after this medication is discontinued. (05 Mar 2000) |
| nicotinic acids | 2-, 3-, or 4-pyridinecarboxylic acids. Pyridine derivatives substituted with a carboxy group at the 2-, 3-, or 4-position. The 3-carboxy derivative (niacin) is active as a vitamin. (12 Dec 1998) |