Linked Life Data

1385952

Source:http://linkedlifedata.com/resource/pubmed/id/1385952

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1992-8-19
pubmed:abstractText
The enzyme DT diaphorase (NAD(P)H dehydrogenase (quinone), EC 1.6.99.2) is unusual in that it can utilize either NADH or NADPH as a co-factor for the reduction of its substrates. We have shown that the intact NAD(P)H molecule is not required and that other reduced pyridinium compounds can also act as co-factors for DT diaphorase. The entire adenine dinucleotide portion of NAD(P)H can be dispensed with entirely and the simplest quaternary (and therefore reducible) derivative of nicotinamide, 1-methylnicotinamide, was as effective as NAD(P)H as a co-factor for the reduction of the quinone, menadione. Nicotinamide 5'-O-benzoyl riboside was also as effective a co-factor as NAD(P)H, whilst nicotinamide ribotide and riboside have a higher Km, and decreased the kcat of DT diaphorase. Nicotinic acid derivatives had little activity. Kinetic analysis indicated that both nicotinamide ribotide and riboside may be interacting with the menadione binding site rather than the NAD(P)H site. Irrespective of the differences between the various reduced pyridinium derivatives in their ability to act as co-factors for the reduction of menadione by DT diaphorase, all the compounds that showed activity in this assay were equally effective co-factors for the reduction of the nitrobenzamide, CB 1954 (5-(aziridin-1-yl)-2,4-dinitrobenzamide). The apparent Km of DT diaphorase for all these co-factors approached zero. It was concluded that co-factor binding is not a rate-limiting step in the nitroreductase activity of DT diaphorase.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-2952
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
25-31
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Identification of novel reduced pyridinium derivatives as synthetic co-factors for the enzyme DT diaphorase (NAD(P)H dehydrogenase (quinone), EC 1.6.99.2).
pubmed:affiliation
Molecular Pharmacology Unit, Institute of Cancer Research, Sutton, Surrey, U.K.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't