Linked Life Data

2339956

Source:http://linkedlifedata.com/resource/pubmed/id/2339956

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1990-6-19
pubmed:abstractText
We have studied the permeability properties of intact peroxisomes and purified peroxisomal membranes from two methylotrophic yeasts. After incorporation of sucrose and dextran in proteoliposomes composed of asolectin and peroxisomal membranes isolated from the yeasts Hansenula polymorpha and Candida boidinii a selective leakage of sucrose occurred indicating that the peroxisomal membranes were permeable to small molecules. Since the permeability of yeast peroxisomal membranes in vitro may be due to the isolation procedure employed, the osmotic stability of peroxisomes was tested during incubations of intact protoplasts in hypotonic media. Mild osmotic swelling of the protoplasts also resulted in swelling of the peroxisomes present in these cells but not in a release of their matrix proteins. The latter was only observed when the integrity of the cells was disturbed due to disruption of the cell membrane during further lowering of the concentration of the osmotic stabilizer. Stability tests with purified peroxisomes indicated that this leak of matrix proteins was not associated with the permeability to sucrose. Various attempts to mimic the in vivo situation and generate a proton motive force across the peroxisomal membranes in order to influence the permeability properties failed. Two different proton pumps were used for this purpose namely bacteriorhodopsin (BR) and reaction center-light-harvesting complex I (RCLH1 complex). After introduction of BR into the membrane of intact peroxisomes generation of a pH-gradient was not or barely detectable. Since this pump readily generated a pH-gradient in pure liposomes, these results strengthened the initial observations on the leakiness of the peroxisomal membrane fragments.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0302-8933
pubmed:author
pubmed:issnType
Print
pubmed:volume
153
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
490-5
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Permeability properties of peroxisomal membranes from yeasts.
pubmed:affiliation
Department of Microbiology, University of Groningen, Haren, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't