EFFECT OF LIPOTEICHOIC ACID ON THERMOTROPIC MEMBRANE-PROPERTIES

Citation
T. Gutberlet et al., EFFECT OF LIPOTEICHOIC ACID ON THERMOTROPIC MEMBRANE-PROPERTIES, Journal of bacteriology, 179(9), 1997, pp. 2879-2883
Citations number
24
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology
Journal title
ISSN journal
0021-9193
Volume
179
Issue
9
Year of publication
1997
Pages
2879 - 2883
Database
ISI
SICI code
0021-9193(1997)179:9<2879:EOLAOT>2.0.ZU;2-S
Abstract
Lipoteichoic acid, diglucosyldiacylglycerol, and phosphatidylglycerol isolated from Staphylococcus aureus were embedded in dipalmitoylglycer ophosphoglycerol vesicles, and their thermotropic influence on this ma trix was studied by differential scanning calorimetry. The natural fat ty acids of phosphatidylglycerol effected peak broadening and a decrea se in molar heat capacity, These effects were more pronounced with the glycolipid, which also increased the main transition temperature. Wit h the lipoteichoic acid mixtures, two broad main transition peaks were observed, possibly due to different levels of lipoteichoic acid in ve sicles. Both peaks showed a further upshift in transition temperatures and a pronounced decrease in molar heat capacity. Since the diacylgly cerol moieties of all three amphiphiles were practically identical, th e differences in the thermotropic effects have to be ascribed to the d ifferent structures of the head groups. Diglucosyldiacylglycerol is pr oposed to exert an additional effect by hydrogen bonding the hydroxyls of the sugar rings to their phospholipid neighbors, The stronger effe ct of lipoteichoic acid points to dynamic interactions of the long hyd rophilic chain with the vesicle surface, which stabilize the membrane structure.