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Infrared spectroscopic study of stratum corneum model membranes prepared from human ceramides, cholesterol, and fatty acids.
Biophys J. 2007 Apr 15; 92(8):2785-95.BJ

Abstract

The outermost layer of the skin, the stratum corneum, consists of corneocytes surrounded by lipid domains. The main lipid classes in stratum corneum are cholesterol, ceramides (CER), and free fatty acids forming two crystalline lamellar phases. However, only limited information is available on whether the various lipid classes participate in the same crystalline lattices or if separate domains are formed within the lipid lamellae. In this article infrared spectroscopic studies are reported of hydrated mixtures prepared from cholesterol, human CER, and free fatty acids. Evaluation of the methylene stretching vibrations revealed a conformational disordering starting at approximately 60 degrees C for all mixtures. Examination of the rotational ordering (scissoring and rocking vibrations) of mixtures prepared from equimolar cholesterol and CER with a variation in the level of free fatty acids showed that at lower free fatty acid content orthorhombic and hexagonal domains coexist in the lipid lamellae. Increasing the fatty acid level to an equimolar cholesterol/CER/fatty acid mixture reveals the dominant presence of an orthorhombic lattice, confirming x-ray diffraction studies. Replacing the protonated free fatty acid chains by their perdeuterated counterparts demonstrates that free fatty acids and CER participate in the same orthorhombic lattice up to a level of slightly less than 1:1:0.75 cholesterol/CER/free fatty acids molar ratio but that free fatty acids also form separate domains within the lipid lamellae at equimolar ratios at room temperature. However, no evidence for this has been observed at 32 degrees C. Extrapolating these findings to the situation in stratum corneum led us conclude that in stratum corneum, fatty acids and CER participate in the orthorhombic lattice at 32 degrees C, the skin temperature.

Authors+Show Affiliations

Leiden/Amsterdam Center for Drug Research, Department of Drug Delivery Technology, Leiden University, 2300 RA Leiden, The Netherlands.No affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

17277189

Citation

Gooris, G S., and J A. Bouwstra. "Infrared Spectroscopic Study of Stratum Corneum Model Membranes Prepared From Human Ceramides, Cholesterol, and Fatty Acids." Biophysical Journal, vol. 92, no. 8, 2007, pp. 2785-95.
Gooris GS, Bouwstra JA. Infrared spectroscopic study of stratum corneum model membranes prepared from human ceramides, cholesterol, and fatty acids. Biophys J. 2007;92(8):2785-95.
Gooris, G. S., & Bouwstra, J. A. (2007). Infrared spectroscopic study of stratum corneum model membranes prepared from human ceramides, cholesterol, and fatty acids. Biophysical Journal, 92(8), 2785-95.
Gooris GS, Bouwstra JA. Infrared Spectroscopic Study of Stratum Corneum Model Membranes Prepared From Human Ceramides, Cholesterol, and Fatty Acids. Biophys J. 2007 Apr 15;92(8):2785-95. PubMed PMID: 17277189.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Infrared spectroscopic study of stratum corneum model membranes prepared from human ceramides, cholesterol, and fatty acids. AU - Gooris,G S, AU - Bouwstra,J A, Y1 - 2007/02/02/ PY - 2007/2/6/pubmed PY - 2007/6/5/medline PY - 2007/2/6/entrez SP - 2785 EP - 95 JF - Biophysical journal JO - Biophys J VL - 92 IS - 8 N2 - The outermost layer of the skin, the stratum corneum, consists of corneocytes surrounded by lipid domains. The main lipid classes in stratum corneum are cholesterol, ceramides (CER), and free fatty acids forming two crystalline lamellar phases. However, only limited information is available on whether the various lipid classes participate in the same crystalline lattices or if separate domains are formed within the lipid lamellae. In this article infrared spectroscopic studies are reported of hydrated mixtures prepared from cholesterol, human CER, and free fatty acids. Evaluation of the methylene stretching vibrations revealed a conformational disordering starting at approximately 60 degrees C for all mixtures. Examination of the rotational ordering (scissoring and rocking vibrations) of mixtures prepared from equimolar cholesterol and CER with a variation in the level of free fatty acids showed that at lower free fatty acid content orthorhombic and hexagonal domains coexist in the lipid lamellae. Increasing the fatty acid level to an equimolar cholesterol/CER/fatty acid mixture reveals the dominant presence of an orthorhombic lattice, confirming x-ray diffraction studies. Replacing the protonated free fatty acid chains by their perdeuterated counterparts demonstrates that free fatty acids and CER participate in the same orthorhombic lattice up to a level of slightly less than 1:1:0.75 cholesterol/CER/free fatty acids molar ratio but that free fatty acids also form separate domains within the lipid lamellae at equimolar ratios at room temperature. However, no evidence for this has been observed at 32 degrees C. Extrapolating these findings to the situation in stratum corneum led us conclude that in stratum corneum, fatty acids and CER participate in the orthorhombic lattice at 32 degrees C, the skin temperature. SN - 0006-3495 UR - https://www.unboundmedicine.com/medline/citation/17277189/Infrared_spectroscopic_study_of_stratum_corneum_model_membranes_prepared_from_human_ceramides_cholesterol_and_fatty_acids_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0006-3495(07)71083-4 DB - PRIME DP - Unbound Medicine ER -