Linked Life Data

6975779

Source:http://linkedlifedata.com/resource/pubmed/id/6975779

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1982-2-25
pubmed:abstractText
Methylenetetrahydrofolate reductase from pig liver has been purified to homogeneity, as judged by several criteria: (i) a single band with a subunit molecular weight of 77,300 following polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate; (ii) a molecular weight determined by amino acid analysis of 74,500 per flavin, in agreement with the subunit molecular weight; and (iii) constant specific activities in the peak fractions during the final chromatography step. The purified enzyme exhibits a typical flavoprotein absorption spectrum. Methylenetetrahydrofolate reductase is a minor constituent of pig liver, and to obtain homogeneous enzyme, a 32,000-fold purification must be accomplished. The preparation described herein attains such purification in 5 steps and with a 14% yield. The enzyme isolated in this fashion is active and stable, and contains a stoichiometric complement of FAD. The enzyme is reducible under anaerobic conditions by 5-deazaflavin/EDTA/light or by NADPH. Reduction of 1 mol of enzyme-bound FAD requires 1.1 mol of NADPH. The reduced enzyme can be reoxidized by (6-R)-methylenetetrahydrofolate, again with nearly 1:1 stoichiometry. Steady state kinetic measurements of the NADPH-methylenetetrahydrofolate oxidoreductase activity give parallel line double reciprocal plots. The turnover number per mol of enzyme-bound flavin is 1600/min under Vmax conditions. The spectrum of the enzyme-bound flavin is significantly perturbed by the binding of S-adenosylmethionine, a metabolite known to be an allosteric modulator of the enzyme.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
257
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
140-5
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1982
pubmed:articleTitle
Purification and properties of methylenetetrahydrofolate reductase from pig liver.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't