Switch to
| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
24
|
| pubmed:dateCreated |
1988-3-18
|
| pubmed:abstractText |
Deamino-NADH/ubiquinone 1 oxidoreductase activity in membrane preparations from Escherichia coli GR19N is 20-50% of NADH/ubiquinone 1 oxidoreductase activity. In comparison, membranes from E. coli IY91, which contain amplified levels of NADH dehydrogenase, exhibit about 100-fold higher NADH/ubiquinone 1 reductase activity but about 20-fold less deamino-NADH/ubiquinone 1 reductase activity. Deamino-NADH/ubiquinone 1 reductase is more sensitive than NADH/ubiquinone 1 reductase activity to inhibition by 3-undecyl-2-hydroxyl-1,4-naphthoquinone, piericidin A, or myxothiazol. Furthermore, GR19N membranes exhibit two apparent Kms for NADH but only one for deamino-NADH. Inside-out membrane vesicles from E. coli GR19N generate a H+ electrochemical gradient (interior positive and acid) during electron transfer from deamino-NADH to ubiquinone 1 that is large and stable relative to that observed with NADH as substrate. Generation of the H+ electrochemical gradient in the presence of deamino-NADH is inhibited by 3-undecyl-2-hydroxy-1,4-naphthoquinone and is not observed in IY91 membrane vesicles or in vesicles from GR19N that are deficient in deamino-NADH/ubiquinone 1 reductase activity. The data provide a strong indication that the E. coli aerobic respiratory chain contains two species of NADH dehydrogenases: (i) an enzyme (NADH dh I) that reacts with deamino-NADH or NADH whose turnover leads to generation of a H+ electrochemical gradient at a site between the primary dehydrogenase and ubiquinone and (ii) an enzyme (NADH dh II) that reacts with NADH exclusively whose turnover does not lead to generation of a H+ electrochemical gradient between the primary dehydrogenase and ubiquinone 1.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Dec
|
| pubmed:issn |
0006-2960
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
1
|
| pubmed:volume |
26
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
7732-7
|
| pubmed:dateRevised |
2007-11-15
|
| pubmed:meshHeading |
pubmed-meshheading:3122832-Aerobiosis,
pubmed-meshheading:3122832-Cell Membrane,
pubmed-meshheading:3122832-Escherichia coli,
pubmed-meshheading:3122832-Kinetics,
pubmed-meshheading:3122832-Membrane Potentials,
pubmed-meshheading:3122832-NAD(P)H Dehydrogenase (Quinone),
pubmed-meshheading:3122832-Oxygen Consumption,
pubmed-meshheading:3122832-Quinone Reductases
|
| pubmed:year |
1987
|
| pubmed:articleTitle |
NADH-ubiquinone oxidoreductases of the Escherichia coli aerobic respiratory chain.
|
| pubmed:affiliation |
Roche Institute of Molecular Biology, Roche Research Center, Nutley, New Jersey 07110.
|
| pubmed:publicationType |
Journal Article
|