Linked Life Data

3040081

Source:http://linkedlifedata.com/resource/pubmed/id/3040081

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1987-10-1
pubmed:abstractText
D-beta-Hydroxybutyrate dehydrogenase (EC 1.1.1.30) is a membrane-bound, lipid-requiring enzyme which has a reactive sulfhydryl in the vicinity of the active center. The spin-probe-spin-label technique has been used to estimate the distance of separation of the reactive sulfhydryl of D-beta-hydroxybutyrate dehydrogenase from the bilayer surface. The reactive sulfhydryl of the enzyme was derivatized with the maleimide spin-label reagent 4-maleimido-2,2,6,6-tetramethylpiperidinyl-1-oxy in the presence of the cofactor NAD+. The derivatized enzyme, inserted (inlaid orientation) into phospholipid vesicles, was titrated with spin probes, either Mn2+ or Gd3+, until the spin-label EPR spectrum was reduced in amplitude to its residual (limiting) value. From this limiting amplitude, the dipolar interaction coefficient was obtained, which is related to the reciprocal of the distance to the sixth power. The radial distances of closest approach of the paramagnetic Mn2+ and Gd3+ ions to the spin-label nitroxide on the enzyme were found to be 18 and 16 A, respectively. These calculated distances were in accord with those determined by comparison with a phosphatidylcholine calibration system having 2,2-dimethyloxazolidinyl-1-oxy spin-labels located at selected positions along the sn-2 fatty acyl chain. Since the distal nitroxide moiety of the maleimide spin-label (17 A from the bilayer surface) is 8 A from the sulfhydryl addition site, the two limiting distances of immersion of the reactive sulfhydryl within the bilayer are 9 and 25 A. The shorter distance is considered more compatible with facile access of the coenzyme to the active site of the enzyme.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2117-30
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Distance estimate of the active center of D-beta-hydroxybutyrate dehydrogenase from the membrane surface.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.