Linked Life Data

3839413

Source:http://linkedlifedata.com/resource/pubmed/id/3839413

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1985-9-12
pubmed:abstractText
Ubiquinone (UQn with n = 2, 3, or 10 isoprenoid groups) was incorporated into small, sonicated vesicles made of dipalmitoylphosphatidylcholine (DPPC) or dimyristoylphosphatidylcholine (DMPC). (1) The accessibility of oxidized UQ in DPPC or DMPC vesicles to the reductant sodium borohydride (NaBH4), measured by UV spectroscopy, was UQ2 greater than UQ3 greater than UQ10 (DPPC) and UQ2 greater than UQ3 approximately UQ10 (DMPC). (2) Catalysis of the reduction of entrapped ferricyanide by exogenous NaBH4 was more effective with UQ2 than UQ10 but was slower with all quinones than reduction by added dithionite. (3) The methoxy protons of UQ2 and UQ3 in DPPC and DMPC vesicles exhibited a single NMR resonance centered at approximately 3.95 ppm, whereas the methoxy groups of UQ10 gave rise to two separate proton resonances, at 3.93 ppm and a more narrow resonance at 3.78 ppm. The UQ10 population characterized by the 3.78 ppm resonance was present at a higher concentration in DPPC than in DMPC vesicles and was relatively insensitive to reduction by NaBH4. (4) UQ10 perturbed the melting temperature (Tm) of DPPC vesicles to a smaller extent (delta Tm = -1 degrees C) than did UQ2 and UQ3 (delta Tm = -3 to -4 degrees C). The combined UV and NMR data imply the following: The UQ10 pool characterized by the 3.78 ppm peak corresponds to a more mobile UQ10 fraction that is not reduced by NaBH4 in 2-3 min and is thought to be localized close to the center of the DPPC bilayer since it has little effect on the DPPC Tm.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2501-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Location and mobility of ubiquinones of different chain lengths in artificial membrane vesicles.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.