2.02012-05-31 13:55:28 -06002015-09-17 15:41:13 -0600ECMDB02078M2MDB000437CyanateThe cyanate ion is an anion consisting of one oxygen atom, one carbon atom, and one nitrogen atom, [OCN], in that order. The cyanate ion possesses 1 unit of negative charge, borne mainly by the nitrogen atom. In organic compounds the cyanate group is a functional group.; The cyanate ion is an ambident nucleophile in nucleophilic substitution because it can react to form an alkyl cyanate R-OCN (exception) or an alkyl isocyanate R-NCO (rule). Aryl cyanates (C6H5OCN) can be formed by a reaction of phenol with cyanogen chloride (ClCN) in the presence of a base. The cyanate ion is relatively non-toxic in comparison with cyanides. Use of this fact is made in cyanide decontamination processes where a permanganate oxidation converts toxic cyanide to safer cyanate. Cyanate can be decomposed by the enzyme cyanate lyase (or cyanase), which is found in bacteria and plants. In particular cyanate can be decomposed to carbamate (ammonia) and carbon dioxide. Alternately the same enzyme can be used to synthesize cyanate using carbamate and carbon dioxide.Cyanic acidHydrogen cyanateHydrogen cyanic acidCNO42.016841.997988627cyanic acidcyanic acid71000-82-3[O-]C#NInChI=1S/CHNO/c2-1-3/h3H/p-1XLJMAIOERFSOGZ-UHFFFAOYSA-MSolidCytosolExtra-organismPeriplasmlogp-1.08logs-0.44solubility1.55e+01 g/llogp-0.54pka_strongest_acidic-1.3pka_strongest_basic-9.9iupaccyanic acidaverage_mass42.0168mono_mass41.997988627smiles[O-]C#NformulaCNOinchiInChI=1S/CHNO/c2-1-3/h3H/p-1inchikeyXLJMAIOERFSOGZ-UHFFFAOYSA-Mpolar_surface_area44.02refractivity9.22polarizability3.16rotatable_bond_count0acceptor_count2donor_count1physiological_charge-1formal_charge0Nitrogen metabolism
The biological process of the nitrogen cycle is a complex interplay among many microorganisms catalyzing different reactions, where nitrogen is found in various oxidation states ranging from +5 in nitrate to -3 in ammonia.
The ability of fixing atmospheric nitrogen by the nitrogenase enzyme complex is present in restricted prokaryotes (diazotrophs). The other reduction pathways are assimilatory nitrate reduction and dissimilatory nitrate reduction both for conversion to ammonia, and denitrification. Denitrification is a respiration in which nitrate or nitrite is reduced as a terminal electron acceptor under low oxygen or anoxic conditions, producing gaseous nitrogen compounds (N2, NO and N2O) to the atmosphere.
Nitrate can be introduced into the cytoplasm through a nitrate:nitrite antiporter NarK or a nitrate / nitrite transporter NarU. Nitrate is then reduced by a Nitrate Reductase resulting in the release of water, an acceptor and a Nitrite. Nitrite can also be introduced into the cytoplasm through a nitrate:nitrite antiporter NarK
Nitrite can be reduced a NADPH dependent nitrite reductase resulting in water and NAD and Ammonia.
Nitrite can interact with hydrogen ion, ferrocytochrome c through a cytochrome c-552 ferricytochrome resulting in the release of ferricytochrome c, water and ammonia
Another process by which ammonia is produced is by a reversible reaction of hydroxylamine with a reduced acceptor through a hydroxylamine reductase resulting in an acceptor, water and ammonia.
Water and carbon dioxide react through a carbonate dehydratase resulting in carbamic acid. This compound reacts spontaneously with hydrogen ion resulting in the release of carbon dioxide and ammonia. Carbon dioxide can interact with water through a carbonic anhydrase resulting in hydrogen carbonate. This compound interacts with cyanate and hydrogen ion through a cyanate hydratase resulting in a carbamic acid.
Ammonia can be metabolized by reacting with L-glutamine and ATP driven glutamine synthetase resulting in ADP, phosphate and L-glutamine. The latter compound reacts with oxoglutaric acid and hydrogen ion through a NADPH dependent glutamate synthase resulting in the release of NADP and L-glutamic acid. L-glutamic acid reacts with water through a NADP-specific glutamate dehydrogenase resulting in the release of oxoglutaric acid, NADPH, hydrogen ion and ammonia.
PW000755ec00910MetabolicABC transportersec02010cyanate degradationThe cyanate degradation pathway begins with the transportation of cyanate into the cytosol through a cynX transporter. Once inside the cytosol cyanate reacts with hydrogen carbonate and a hydrogen ion through a cyanase resulting in the release of carbon dioxide and carbamate. Carbamate reacts spontaneously with hydrogen resulting in the release of ammonium and carbon dioxide. Carbon dioxide reacts with water through carbonic anhydrase resulting in the release of hydrogen ion and hydrogen carbonate.PW002099Metaboliccyanate degradationCYANCAT-PWYSpecdb::CMs151844Specdb::MsMs29543Specdb::MsMs29544Specdb::MsMs29545Specdb::MsMs36101Specdb::MsMs36102Specdb::MsMs36103Specdb::MsMs1218088Specdb::MsMs1218089Specdb::MsMs1218090Specdb::MsMs2800327Specdb::MsMs2800328Specdb::MsMs2800329Specdb::MsMs2878334Specdb::MsMs2878335Specdb::MsMs2878336HMDB0207854094771C0141729195CPD-69CyanateKeseler, I. M., Collado-Vides, J., Santos-Zavaleta, A., Peralta-Gil, M., Gama-Castro, S., Muniz-Rascado, L., Bonavides-Martinez, C., Paley, S., Krummenacker, M., Altman, T., Kaipa, P., Spaulding, A., Pacheco, J., Latendresse, M., Fulcher, C., Sarker, M., Shearer, A. G., Mackie, A., Paulsen, I., Gunsalus, R. P., Karp, P. D. (2011). "EcoCyc: a comprehensive database of Escherichia coli biology." Nucleic Acids Res 39:D583-D590.21097882Kanehisa, M., Goto, S., Sato, Y., Furumichi, M., Tanabe, M. (2012). "KEGG for integration and interpretation of large-scale molecular data sets." Nucleic Acids Res 40:D109-D114.22080510van der Werf, M. J., Overkamp, K. M., Muilwijk, B., Coulier, L., Hankemeier, T. (2007). "Microbial metabolomics: toward a platform with full metabolome coverage." Anal Biochem 370:17-25.17765195Hseu, Tzong Hsiung; Lan, Shih Li; Yang, Min Der. Cyanate from alkaline hydrolysis of cyanogen bromide-activated polysaccharides. Analytical Biochemistry (1981), 116(1), 181-4. http://hmdb.ca/system/metabolites/msds/000/001/661/original/HMDB02078.pdf?1358461679Cyanate hydrataseP00816CYNS_ECOLIcynShttp://ecmdb.ca/proteins/P00816.xmlOuter membrane protein NP77747OMPN_ECOLIompNhttp://ecmdb.ca/proteins/P77747.xmlOuter membrane pore protein EP02932PHOE_ECOLIphoEhttp://ecmdb.ca/proteins/P02932.xmlOuter membrane protein FP02931OMPF_ECOLIompFhttp://ecmdb.ca/proteins/P02931.xmlCyanate transport protein cynXP17583CYNX_ECOLIcynXhttp://ecmdb.ca/proteins/P17583.xmlOuter membrane protein CP06996OMPC_ECOLIompChttp://ecmdb.ca/proteins/P06996.xmlCyanate + 3 Hydrogen ion + Hydrogen carbonate >2 Carbon dioxide + AmmoniumCyanate + Hydrogen ion + Hydrogen carbonate <> Carbon dioxide + Carbamic acidR03546R524-RXNCyanate + Hydrogen carbonate + Hydrogen ion > Carbamic acid + Carbon dioxideR524-RXNCyanate + Carbonic acid + 2 Hydrogen ion > Ammonia +2 Carbon dioxideCyanate + Hydrogen carbonate + 2 Hydrogen ion + Carbamic acid <> Ammonia +2 Carbon dioxideR10079 Hydrogen carbonate + Cyanate + Hydrogen ion + Cyanate > Carbamic acidPW_R002431Cyanate + Hydrogen ion + Hydrogen carbonate <> Carbon dioxide + Carbamic acidCyanate + Hydrogen ion + Hydrogen carbonate <> Carbon dioxide + Carbamic acid