Abstract
The influence of carbohydrate structure on the ordering of glycosphingolipids (GSLs) and surrounding phospholipids was investigated in monolayers at the air-water interface. Binary mixtures composed of GSLs, chosen to span a range of carbohydrate complexity, and zwitterionic dipalmitoylphosphatidylcholine phospholipid, were studied. X-ray reflectivity was used to measure the out-of-plane structure of the monolayers and characterize the extension and conformation of the GSL carbohydrates. Using synchrotron grazing incidence x-ray diffraction, the in-plane packing of the lipid acyl chains and the area per molecule within ordered domains were characterized at different mole ratios of the two components. Our findings indicate that GSL-containing mixtures, regardless of the carbohydrate size, enhance the ordering of the surrounding lipids, resulting in a larger fraction of ordered phase of the monolayer and greater dimensions of the ordered domains. Reduction of the averaged area per molecule within the ordered domains was also observed but only in the cases where there was a size mismatch between the phospholipid headgroups and GSL components, suggesting that the condensation mechanism involves the relief of steric interactions between headgroups in mixtures.
| Original language | English |
|---|---|
| Pages (from-to) | 1103-1115 |
| Number of pages | 13 |
| Journal | Biophysical Journal |
| Volume | 114 |
| Issue number | 5 |
| DOIs | |
| State | Published - Mar 13 2018 |
| Externally published | Yes |
Funding
This work was supported by the National Science Foundation (NSF) (MCB-0616249; MCB-0920316; MCB-1413613) and the NSF-supported MRSEC program at the University of Chicago (DMR-1420709). S.L.F. is grateful for the support of a National Science Foundation Graduate Research Fellowship and an I2CAM travel award (NSF grant DMR 0645461) for the x-ray work. E.Y.C. is grateful for the support by the National Institutes of Health Ruth L. Kirschstein National Research Service Award Individual Fellowship (AG025649) and an I2CAM travel award (NSF grant DMR 0645461) for the x-ray work. J.M. was supported by the Los Alamos National Laboratory under Department of Energy (DOE) contract W7405-ENG-36, the DOE Office of Basic Energy Science. This work was supported by the National Science Foundation (NSF) ( MCB-0616249 ; MCB-0920316 ; MCB-1413613 ) and the NSF-supported MRSEC program at the University of Chicago ( DMR-1420709 ). S.L.F. is grateful for the support of a National Science Foundation Graduate Research Fellowship and an I2CAM travel award ( NSF grant DMR 0645461 ) for the x-ray work. E.Y.C. is grateful for the support by the National Institutes of Health Ruth L. Kirschstein National Research Service Award Individual Fellowship ( AG025649 ) and an I2CAM travel award ( NSF grant DMR 0645461 ) for the x-ray work. J.M. was supported by the Los Alamos National Laboratory under Department of Energy (DOE) contract W7405-ENG-36 , the DOE Office of Basic Energy Science .