Linked Life Data

8631754

Source:http://linkedlifedata.com/resource/pubmed/id/8631754

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
1996-7-3
pubmed:abstractText
Neuronal nitric-oxide (NO) synthase contains FAD, FMN, heme, and tetrahydrobiopterin as prosthetic groups and represents a multifunctional oxidoreductase catalyzing oxidation of L-arginine to L-citrulline and NO, reduction of molecular oxygen to superoxide, and electron transfer to cytochromes. To investigate how binding of the prosthetic heme moiety is related to enzyme activities, cofactor, and L-arginine binding, as well as to secondary and quaternary protein structure, we have purified and characterized heme-deficient neuronal NO synthase. The heme-deficient enzyme, which had preserved its cytochrome c reductase activity, contained FAD and FMN, but virtually no tetrahydrobiopterin, and exhibited only marginal NO synthase activity. By means of gel filtration and static light scattering, we demonstrate that the heme-deficient enzyme is a monomer and provide evidence that heme is the sole prosthetic group controlling the quaternary structure of neuronal NO synthase. CD spectroscopy showed that most of the structural elements found in the dimeric holoenzyme were conserved in heme-deficient monomeric NO synthase. However, in spite of being properly folded, the heme-deficient enzyme did bind neither tetrahydrobiopterin nor the substrate analog N(G)-nitro-L-arginine. Our results demonstrate that the prosthetic heme group of neuronal NO synthase is requisite for dimerization of enzyme subunits and for the binding of amino acid substrate and tetrahydrobiopterin.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
29
pubmed:volume
271
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7336-42
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:8631754-Animals, pubmed-meshheading:8631754-Arginine, pubmed-meshheading:8631754-Binding Sites, pubmed-meshheading:8631754-Biopterin, pubmed-meshheading:8631754-Brain, pubmed-meshheading:8631754-Chromatography, Gel, pubmed-meshheading:8631754-Circular Dichroism, pubmed-meshheading:8631754-Citrulline, pubmed-meshheading:8631754-Flavin Mononucleotide, pubmed-meshheading:8631754-Flavin-Adenine Dinucleotide, pubmed-meshheading:8631754-Heme, pubmed-meshheading:8631754-Isoenzymes, pubmed-meshheading:8631754-Light, pubmed-meshheading:8631754-Macromolecular Substances, pubmed-meshheading:8631754-Neurons, pubmed-meshheading:8631754-Nitric Oxide Synthase, pubmed-meshheading:8631754-Nitroarginine, pubmed-meshheading:8631754-Protein Conformation, pubmed-meshheading:8631754-Protein Structure, Secondary, pubmed-meshheading:8631754-Rats, pubmed-meshheading:8631754-Scattering, Radiation, pubmed-meshheading:8631754-Thermodynamics
pubmed:year
1996
pubmed:articleTitle
Characterization of heme-deficient neuronal nitric-oxide synthase reveals a role for heme in subunit dimerization and binding of the amino acid substrate and tetrahydrobiopterin.
pubmed:affiliation
Institut für Pharmakologie und Toxikologie, Karl-Franzens-Universität Graz, Austria.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't