Linked Life Data

1435870

Source:http://linkedlifedata.com/resource/pubmed/id/1435870

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1992-12-21
pubmed:abstractText
The membrane potential and pH gradient over the plasma membrane of the protozoan parasite Trypanosoma brucei were measured with radioactive indicators in combination with the silicone oil centrifugation technique over a range of temperatures. At 37 degrees C a small membrane potential and pH gradient of similar magnitude, but of opposite polarity, were measured. The resulting electrochemical proton gradient was almost zero. However, when the temperature was lowered from 37 degrees C to 22 degrees C, the internal pH was kept constant independent of the external pH and a membrane potential of between -100 and -150 mV was measured, depending on the external pH. Measurements at various temperatures between 15 degrees C and 37 degrees C revealed that above 26 degrees C the membrane potential collapsed and that this collapse correlated with a sudden increase in membrane fluidity. The uptake of 2-deoxy-D-glucose and of pyruvate, which are both mediated by facilitated diffusion carriers in the plasma membrane of the trypanosome, were also affected by this sudden increase in fluidity of the membrane. The overall rate of the conversion of glucose into its metabolites, which is independent of the plasma membrane, varied only gradually. We conclude (i) that major changes occur in the plasma membrane of T. brucei around 26 degrees C, that affect all membrane related processes; (ii) that the electrochemical proton gradient plays a minor role in the energy metabolism of T. brucei when it resides in the bloodstream of the mammalian host at 37 degrees C; and (iii) that below 26 degrees C an electrochemical proton gradient is maintained over the plasma membrane.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0166-6851
pubmed:author
pubmed:issnType
Print
pubmed:volume
55
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
21-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
The electrochemical proton gradient in the bloodstream form of Trypanosoma brucei is dependent on the temperature.
pubmed:affiliation
Research Unit for Tropical Diseases, International Institute of Cellular and Molecular Pathology, Brussels, Belgium.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't