Linked Life Data

4386790

Source:http://linkedlifedata.com/resource/pubmed/id/4386790

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1968-12-9
pubmed:abstractText
Optochin-resistant mutant and wild-type diaphorases were purified approximately 300-fold by a combination of batch adsorption and column chromatography with diethylaminoethyl cellulose, and were characterized with regard to their pH optima, sensitivity to optochin inhibition and heat inactivation, Michaelis constants with flavine mononucleotide (FMN) and reduced nicotinamide adenine dinucleotide (NADH), and inhibition constants with optochin hydrochloride. The pH optima of the purified diaphorases were similar, but the purified diaphorases from the optochin-resistant strains were approximately four to five times more resistant to heat inactivation at 45 C than was the wild-type diaphorase. Purified diaphorase preparations from the optochin-resistant pneumococci had greater activities per milligram of protein and were more resistant to optochin inhibition than the preparation from the optochin-sensitive pneumococcus. Michaelis constants for FMN and NADH were similar; however, the inhibition constants of the optochin-resistant diaphorases were four to eight times greater than that of the optochin-sensitive diaphorase. Optochin hydrochloride produced a noncompetitive type of inhibition with FMN as substrate but a competitive type of inhibition with NADH as substrate. Optochin hydrochloride produced an approximately 10-fold increase in the Michaelis constant for NADH. The concentration of drug required to produce this effect was, however, greater with the mutant diaphorases than with the wild-type diaphorase. Optochin hydrochloride quenched the fluorescence of riboflavine. This phenomenon did not appear to be related to the diaphorase-inhibitory activity of the drug, however, since the pH requirements of the two reactions were different. Quenching of riboflavine fluorescence by optochin hydrochloride increased with a rise in pH, whereas inhibition of diaphorase activity by optochin hydrochloride was greater at pH 6.8 than at pH 7.6.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9193
pubmed:author
pubmed:issnType
Print
pubmed:volume
96
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1029-36
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1968
pubmed:articleTitle
Purification and properties of mutant and wild-type diaphorases from Diplococcus pneumoniae.
pubmed:publicationType
Journal Article