Linked Life Data

6509018

Source:http://linkedlifedata.com/resource/pubmed/id/6509018

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
22
pubmed:dateCreated
1985-1-31
pubmed:abstractText
D-beta-Hydroxybutyrate dehydrogenase is a lipid-requiring enzyme with a specific requirement of lecithin for function. The purified enzyme devoid of lipid (apodehydrogenase) is inactive but can be reactivated by forming a complex with phospholipid containing lecithin. We find that, of the six half cysteines present in D-beta-hydroxybutyrate dehydrogenase, only two are in the reduced form and available for modification with N-ethylmaleimide, even after denaturation in sodium dodecyl sulfate. Diamide treatment of either the inactive apodehydrogenase or the active enzyme-phospholipid complex resulted in complete loss of enzymic activity, the apodehydrogenase being assayed after addition of phospholipid. The inactivation by diamide can be reversed by the addition of dithiothreitol with full recovery of activity. Derivatization using N-[14C]ethylmaleimide showed that diamide modified only one sulfhydryl per enzyme monomer. The other sulfhydryl appears not to be essential for function since full activity can be restored after this sulfhydryl had been covalently derivatized with N-ethylmaleimide. Protein cross-linking was not observed after diamide modification of D-beta-hydroxybutyrate dehydrogenase, indicating that a disulfide bridge was not formed between enzyme subunits. The diamide-modified enzyme retains the ability to bind coenzyme, NAD(H), as detected by quenching of the intrinsic fluorescence of the protein. However, resonance energy transfer from protein to bound NADH and enhancement of NADH fluorescence were not observed, indicating that diamide modification of the protein alters the nucleotide binding site.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
23
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5142-7
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Reversible modification of D-beta-hydroxybutyrate dehydrogenase by diamide.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't