Biomaterial Database

Characterisation of the pterin molybdenum cofactor in dimethylsulfoxide reductase of Rhodobacter capsulatus. 1997

P S Solomon, and I Lane, and G R Hanson, and A G McEwan

Department of Microbiology, The University of Queensland, Brisbane, Australia.

Analysis of dimethylsulfoxide reductase from Rhodobacter capsulatus showed that it contained 1 mol Mo and 2 mol GMP. This indicates that the molybdenum cofactor in dimethylsulfoxide reductase is bis(molybdopterin guanine dinucleotide) molybdenum. The absorption spectrum of the molybdopterin guanine dinucleotide released from dimethylsulfoxide reductase after denaturation of the holoenzyme was compared with those of pterin standards of known redox state. The spectra were most similar to pterin standards in the dihydro state and oxidised state. The reduction of 2,6-dichloroindophenol by molybdopterin guanine dinucleotide released from dimethylsulfoxide reductase and by pterin standards was also measured and approximately 2 mol electrons/2 mol molybdopterin guanine dinucleotide were found to reduce 2,6-dichloroindophenol. These results are consistent with the presence of one molybdopterin guanine dinucleotide moiety with a pyrazine ring at the oxidation level of a dihydropteridine and one molybdopterin guanine dinucleotide moiety with a pyrazine ring at the oxidation level of a fully aromatic pteridine. It is suggested that the pyrazine ring of Q-molybdopterin guanine dinucleotide is fully aromatic and contains a 5,6 double bond.

UI	MeSH Term	Description	Entries
D007506	Iron-Sulfur Proteins	A group of proteins possessing only the iron-sulfur complex as the prosthetic group. These proteins participate in all major pathways of electron transport: photosynthesis, respiration, hydroxylation and bacterial hydrogen and nitrogen fixation.	Iron-Sulfur Protein,Iron Sulfur Proteins,Iron Sulfur Protein,Protein, Iron-Sulfur,Proteins, Iron Sulfur,Proteins, Iron-Sulfur,Sulfur Proteins, Iron
D008667	Metalloproteins	Proteins that have one or more tightly bound metal ions forming part of their structure. (Dorland, 28th ed)	Metalloprotein
D008982	Molybdenum	A metallic element with the atomic symbol Mo, atomic number 42, and atomic weight 95.95. It is an essential trace element, being a component of the enzymes xanthine oxidase, aldehyde oxidase, and nitrate reductase.	Molybdenum-98,Molybdenum 98
D009942	Organometallic Compounds	A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)	Metallo-Organic Compound,Metallo-Organic Compounds,Metalloorganic Compound,Organometallic Compound,Metalloorganic Compounds,Compound, Metallo-Organic,Compound, Metalloorganic,Compound, Organometallic,Compounds, Metallo-Organic,Compounds, Metalloorganic,Compounds, Organometallic,Metallo Organic Compound,Metallo Organic Compounds
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D010088	Oxidoreductases	The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)	Dehydrogenases,Oxidases,Oxidoreductase,Reductases,Dehydrogenase,Oxidase,Reductase
D010710	Phosphates	Inorganic salts of phosphoric acid.	Inorganic Phosphate,Phosphates, Inorganic,Inorganic Phosphates,Orthophosphate,Phosphate,Phosphate, Inorganic
D011489	Protein Denaturation	Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.	Denaturation, Protein,Denaturations, Protein,Protein Denaturations
D011621	Pteridines	Compounds based on pyrazino[2,3-d]pyrimidine which is a pyrimidine fused to a pyrazine, containing four NITROGEN atoms.	1,3,5,8-Tetraazanaphthalene,Pteridine,Pteridinone,Pyrazino(2,3-d)pyrimidine,Pyrazinopyrimidine,Pyrazinopyrimidines,Pyrimido(4,5-b)pyrazine,Pteridinones
D011622	Pterins	Compounds based on 2-amino-4-hydroxypteridine.	Pterin