Related Experiment Video
Updated: Oct 5, 2026
Neutron Spin Echo Spectroscopy as a Unique Probe for Lipid Membrane Dynamics and Membrane-Protein Interactions
Published on: May 27, 2021
Structure-function relationship of a single double bond: the difference in lamellar phase behaviors between ceramides
Adina Eichner1, Thomas Hauß2, Tomáš Havrišák3
1Department of Dermatology and Venereology, Martin Luther University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120 Halle (Saale), Germany; Institute of Applied Dermatopharmacy at Martin Luther University Halle-Wittenberg, Weinbergweg 23, 06120 Halle (Saale), Germany.
Abstract:
The barrier function of mammalian skin is closely related to the unique structure of the complex lipid matrix of the stratum corneum. Within this matrix, the heterogeneous group of ceramides plays a key role in determining barrier properties. As native stratum corneum is highly complex, simplified stratum corneum lipid mixture models can be used to efficiently elucidate their detailed structural arrangement. Here, the application of selected ceramide subspecies with defined chain lengths and head group structures in monomeric lipid mixture models, i.e. containing only a single ceramide subspecies, was found to be meaningful for a step-by-step evaluation of the distinct effects of the individual ceramide. In the present work, non-hydroxylated N-acyl chain ceramides with sphingosine and dihydrosphingosine bases with acyl chain lengths of C18, each fully protiated or partially deuterated, were obtained by chemical syntheses. As sphingosine and dihydrosphingosine-based ceramides differ just in a single double bond at the C4-C5 position of the sphingoid base, the aim of this study was to elucidate the effect of the double bond in the ceramide head groups on the lamellar phase behavior of ceramides incorporated into simplified monomeric stratum corneum lipid model membranes. The neutron diffraction studies reveled distinct differences, e.g. in unit cell dimensions with 44.1 Å for ceramide [NS] vs 46.0 Å for ceramide [NdS], with ceramide [NdS] presented a more condensed chain packing in the unit cell center. In addition, with the ceramide [NS]-d3 sample, the formation of a long phase with unit cell dimension of 75.5 Å was observed.
Related Concept Videos
01:35Asymmetric Lipid Bilayer
01:28Structures of Carboxylic Acid Derivatives
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the unhybridized p...
01:16Structure of Conjugated Dienes
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
02:33Stereoisomerism of Cyclic Compounds
02:06Newman Projections
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as conformers.
01:28Stability of Conjugated Dienes
A comparison of the enthalpies of hydrogenation of dienes reveals that conjugated dienes release less heat on hydrogenation, rendering them more stable than their nonconjugated analogs.