Linked Life Data

8639693

Source:http://linkedlifedata.com/resource/pubmed/id/8639693

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1996-7-17
pubmed:abstractText
Recent literature has suggested that the depression of the phase transition temperature (Tm) in dry phospholipids by sugars may be ascribed to vitrification of the stabilizing solute, rather than by the direct interaction between sugar and phospholipid we have proposed. Koster et al. ((1994) Biochim. Biophys. Acta 1193, 143-150) claim that the only necessity is that the glass transition (Tg) for the sugar exceed Tm for the lipid. Evidence is presented in the present paper that this is not sufficient. Based on the vitrification hypothesis of Koster et al., the predicted order of effectiveness in depressing Tm in dry dipalmitoylphosphatidylcholine (DPPC) is dextran > or = hydroxyethyl starch > stachyose > raffinose > trehalose > sucrose > glucose. In fact, the opposite order was seen. The effect of raffinose, sucrose, or trehalose on Tm in dry DPPC depends on the thermal history of the sample, as we have reported previously. When DPPC dried with trehalose is heated for the first time, Tm is about 55 degrees C, but on the second and subsequent heating scans Tm falls to about 25 degrees C. Koster et al. suggest that this effect is due to heating the sample above Tg rather than to melting the hydrocarbon chains. We present evidence here that all that is required is for the chains to be melted. Further, we show that retention of residual water by DPPC dried with trehalose depends on the drying temperature, but is independent of drying temperature with glucose, a finding that is consistent with direct interaction. We conclude that vitrification is not in itself sufficient to depress Tm in dry phospholipids.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
1280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
187-96
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Is vitrification involved in depression of the phase transition temperature in dry phospholipids?
pubmed:affiliation
Section of Molecular and Cellular Biology, University of California, Davis 95616, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.