Back to Search
Start Over
Cholesterol's interactions with serine phospholipids — A comparison of N-palmitoyl ceramide phosphoserine with dipalmitoyl phosphatidylserine
- Source :
-
BBA: Biomembranes . Feb2013, Vol. 1828 Issue 2, p785-791. 7p. - Publication Year :
- 2013
-
Abstract
- Abstract: In this study we have prepared ceramide phosphoserine (CerPS) and examined its sterol-interacting properties. CerPS is a hydrogen-bonding sphingolipid, but its head group differs from that found in sphingomyelin (SM). Based on diphenylhexatriene steady-state anisotropy measurements, we observed that fully hydrated N-palmitoyl CerPS had a gel-to-liquid crystalline phase transition temperature of about 51°C in 50mM sodium phosphate buffer (pH 7.4). This was close to the Tm measured for 1,2-dipalmitoyl-sn-glycero-3-phosphoserine (DPPS) bilayers (Tm 50.5°C). Based on cholestatrienol (CTL) quenching experiments in liquid disordered ternary bilayers (containing 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphcholine; POPC), cholesterol/CTL formed sterol-enriched ordered domains with CerPS. These had similar thermostability as the sterol domains formed with N-palmitoyl SM. Cholesterol failed to form sterol-enriched ordered domains with DPPS under comparable conditions. Based on the equilibrium partitioning of CTL, we observed that the affinity of sterol for bilayers containing POPC/CerPS/cholesterol (6:3:1 by mol) was much higher than the affinity measured for control fluid POPC/cholesterol (9:1 by mol) bilayers, but slightly less than seen for comparable PSM-containing bilayers. We conclude that the phosphoserine head group was less efficient than the phosphocholine head group in stabilizing sterol/sphingolipid interaction. However, hydrogen bonding apparently can overcome some of the negative effects of the phosphoserine head group, since CerPS interacted more favorably with cholesterol compared to DPPS. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 00052736
- Volume :
- 1828
- Issue :
- 2
- Database :
- Academic Search Index
- Journal :
- BBA: Biomembranes
- Publication Type :
- Academic Journal
- Accession number :
- 84574548
- Full Text :
- https://doi.org/10.1016/j.bbamem.2012.11.009