| pubmed-article:10559214 | rdf:type | pubmed:Citation | lld:pubmed |
| pubmed-article:10559214 | lifeskim:mentions | umls-concept:C0318041 | lld:lifeskim |
| pubmed-article:10559214 | lifeskim:mentions | umls-concept:C0016223 | lld:lifeskim |
| pubmed-article:10559214 | lifeskim:mentions | umls-concept:C1427984 | lld:lifeskim |
| pubmed-article:10559214 | lifeskim:mentions | umls-concept:C0007382 | lld:lifeskim |
| pubmed-article:10559214 | lifeskim:mentions | umls-concept:C0441712 | lld:lifeskim |
| pubmed-article:10559214 | lifeskim:mentions | umls-concept:C1295213 | lld:lifeskim |
| pubmed-article:10559214 | pubmed:issue | 47 | lld:pubmed |
| pubmed-article:10559214 | pubmed:dateCreated | 1999-12-14 | lld:pubmed |
| pubmed-article:10559214 | pubmed:abstractText | 2-Hydroxybiphenyl 3-monooxygenase (EC 1.14.13.44) from Pseudomonas azelaica HBP1 is an FAD-dependent aromatic hydroxylase that catalyzes the conversion of 2-hydroxybiphenyl to 2, 3-dihydroxybiphenyl in the presence of NADH and oxygen. The catalytic mechanism of this three-substrate reaction was investigated at 7 degrees C by stopped-flow absorption spectroscopy. Various individual steps associated with catalysis were readily observed at pH 7.5, the optimum pH for enzyme turnover. Anaerobic reduction of the free enzyme by NADH is a biphasic process, most likely reflecting the presence of two distinct enzyme forms. Binding of 2-hydroxybiphenyl stimulated the rate of enzyme reduction by NADH by 2 orders of magnitude. The anaerobic reduction of the enzyme-substrate complex involved the formation of a transient charge-transfer complex between the reduced flavin and NAD(+). A similar transient intermediate was formed when the enzyme was complexed with the substrate analog 2-sec-butylphenol or with the non-substrate effector 2,3-dihydroxybiphenyl. Excess NAD(+) strongly stabilized the charge-transfer complexes but did not give rise to the appearance of any intermediate during the reduction of uncomplexed enzyme. Free reduced 2-hydroxybiphenyl 3-monooxygenase reacted rapidly with oxygen to form oxidized enzyme with no appearance of intermediates during this reaction. In the presence of 2-hydroxybiphenyl, two consecutive spectral intermediates were observed which were assigned to the flavin C(4a)-hydroperoxide and the flavin C(4a)-hydroxide, respectively. No oxygenated flavin intermediates were observed when the enzyme was in complex with 2, 3-dihydroxybiphenyl. Monovalent anions retarded the dehydration of the flavin C(4a)-hydroxide without stabilization of additional intermediates. The kinetic data for 2-hydroxybiphenyl 3-monooxygenase are consistent with a ternary complex mechanism in which the aromatic substrate has strict control in both the reductive and oxidative half-reaction in a way that reactions leading to substrate hydroxylation are favored over those leading to the futile formation of hydrogen peroxide. NAD(+) release from the reduced enzyme-substrate complex is the slowest step in catalysis. | lld:pubmed |
| pubmed-article:10559214 | pubmed:language | eng | lld:pubmed |
| pubmed-article:10559214 | pubmed:journal | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:10559214 | pubmed:citationSubset | IM | lld:pubmed |
| pubmed-article:10559214 | pubmed:chemical | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:10559214 | pubmed:chemical | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:10559214 | pubmed:chemical | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:10559214 | pubmed:status | MEDLINE | lld:pubmed |
| pubmed-article:10559214 | pubmed:month | Nov | lld:pubmed |
| pubmed-article:10559214 | pubmed:issn | 0021-9258 | lld:pubmed |
| pubmed-article:10559214 | pubmed:author | pubmed-author:van BerkelW... | lld:pubmed |
| pubmed-article:10559214 | pubmed:author | pubmed-author:KohlerH PHP | lld:pubmed |
| pubmed-article:10559214 | pubmed:author | pubmed-author:SuskeW AWA | lld:pubmed |
| pubmed-article:10559214 | pubmed:issnType | Print | lld:pubmed |
| pubmed-article:10559214 | pubmed:day | 19 | lld:pubmed |
| pubmed-article:10559214 | pubmed:volume | 274 | lld:pubmed |
| pubmed-article:10559214 | pubmed:owner | NLM | lld:pubmed |
| pubmed-article:10559214 | pubmed:authorsComplete | Y | lld:pubmed |
| pubmed-article:10559214 | pubmed:pagination | 33355-65 | lld:pubmed |
| pubmed-article:10559214 | pubmed:dateRevised | 2006-11-15 | lld:pubmed |
| pubmed-article:10559214 | pubmed:meshHeading | pubmed-meshheading:10559214... | lld:pubmed |
| pubmed-article:10559214 | pubmed:meshHeading | pubmed-meshheading:10559214... | lld:pubmed |
| pubmed-article:10559214 | pubmed:meshHeading | pubmed-meshheading:10559214... | lld:pubmed |
| pubmed-article:10559214 | pubmed:meshHeading | pubmed-meshheading:10559214... | lld:pubmed |
| pubmed-article:10559214 | pubmed:meshHeading | pubmed-meshheading:10559214... | lld:pubmed |
| pubmed-article:10559214 | pubmed:meshHeading | pubmed-meshheading:10559214... | lld:pubmed |
| pubmed-article:10559214 | pubmed:meshHeading | pubmed-meshheading:10559214... | lld:pubmed |
| pubmed-article:10559214 | pubmed:year | 1999 | lld:pubmed |
| pubmed-article:10559214 | pubmed:articleTitle | Catalytic mechanism of 2-hydroxybiphenyl 3-monooxygenase, a flavoprotein from Pseudomonas azelaica HBP1. | lld:pubmed |
| pubmed-article:10559214 | pubmed:affiliation | Department of Microbiology, Swiss Federal Institute of Environmental Sciences and Technology (EAWAG), CH-8600 Dübendorf, The Netherlands. | lld:pubmed |
| pubmed-article:10559214 | pubmed:publicationType | Journal Article | lld:pubmed |
| pubmed-article:10559214 | pubmed:publicationType | Research Support, Non-U.S. Gov't | lld:pubmed |
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| http://linkedlifedata.com/r... | pubmed:referesTo | pubmed-article:10559214 | lld:pubmed |
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| http://linkedlifedata.com/r... | pubmed:referesTo | pubmed-article:10559214 | lld:pubmed |
