Calorimetric and Electron Spin Resonance Examination of Lipid Phase Transitions in Human Stratum Corneum: Molecular Basis for Normal Cohesion and Abnormal Desquamation in Recessive X-Linke Ichthyosis
| Autor: | Mary L. Williams, William Z. Plachy, Peter M. Elias, Selwyn J. Rehfeld |
|---|---|
| Rok vydání: | 1988 |
| Předmět: |
Phase transition
Palmitic Acid Oleic Acids Palmitic Acids Dermatology Calorimetry Biochemistry law.invention Spin probe Desquamation Differential scanning calorimetry law Stratum corneum medicine Cell Adhesion Humans Electron paramagnetic resonance Molecular Biology Sex Chromosome Aberrations Skin X-linked ichthyosis Calorimetry Differential Scanning Chemistry Ichthyosis Electron Spin Resonance Spectroscopy Cell Biology medicine.disease Lipids medicine.anatomical_structure Cholesterol Models Chemical Biophysics Butanes lipids (amino acids peptides and proteins) Nitrogen Oxides Spin Labels Cholesterol Esters medicine.symptom Oleic Acid |
| Zdroj: | Journal of Investigative Dermatology. 91(5):499-505 |
| ISSN: | 0022-202X |
| DOI: | 10.1111/1523-1747.ep12476654 |
| Popis: | Lipids appear to play a critical role as regulators of stratum corneum desquamation. In this study, we observed discrete lipid phase transitions at physiologic temperatures in both normal human scale (NHS) and in lipid extracts of NHS by differential scanning calorimetry. In contrast, such thermal transitions were not observed in recessive x-linked ichthyosis scale (RXLIS). To gain further insight into the molecular basis of the lipid phase transitions in NHS vs. RXLIS, comparable samples were evaluated by electron spin resonance, utilizing the perdeuterated probe, di-t-butyl nitroxide. Upon electron spin resonance analysis, both NHS and RXLIS demonstrated thermal phase transitions in the physiologic range; however, the nature of the lipid environments in each type varied. Whereas the environment of the spin probe was more polar in NHS than in RXLIS, the spin probe partitioned into a more "fluid" environment in RXLIS; i.e., the spin probe was more mobile in RXLIS than in NHS lipid matrices. Because an alteration in the cholesteryl sulfate: cholesterol ratio is the primary lipid abnormality in RXLIS, model cholesterol-fatty acid-cholesteryl sulfate mixtures were prepared in proportion to the lipid composition of NHS and RXLIS. Differences were observed in both thermal transitions and in lipid microenvironments in these mixtures that paralleled those observed in scale samples. Based on these results, a model is proposed that invokes abnormal hydrogen bonding, due to increased cholesteryl sulfate, as the mechanism for the abnormal desquamation in recessive X-linked ichthyosis. |
| Databáze: | OpenAIRE |
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