Nitrogen dioxide solubility and permeation in lipid membranes
Santiago Signorelli1, Matías N Möller, E Laura Coitiño
1Laboratorio de Química Teórica y Computacional, Universidad de la República, Iguá, Montevideo, Uruguay. ssignorelli@fcien.edu.uy
Archives of Biochemistry and Biophysics
|June 28, 2011
Summary
Nitrogen dioxide (NO2) readily crosses lipid membranes. This study estimates NO2 solubility and permeability, finding cell membranes do not significantly impede its transport.
Area of Science:
- Biochemistry
- Environmental Science
- Physical Chemistry
Background:
- Nitrogen dioxide (NO2) is a biologically relevant oxidant and air pollutant.
- NO2's interaction with cell membranes, particularly its diffusion, is poorly understood.
- Limited experimental data exists on NO2 solubility in lipid phases.
Purpose of the Study:
- To estimate the permeability of lipid membranes to nitrogen dioxide (NO2).
- To determine the solubility of NO2 in lipid environments.
- To elucidate the role of cell membranes in NO2 transport.
Main Methods:
- Utilized quantum calculations and Tomasi's Polarizable Continuum Model to compute gas solubility.
- Employed a mixed approach combining theoretical calculations with experimental data validation for related gases.
- Estimated partition coefficients for NO2 in n-octanol/water and lipid membrane/water systems.
Main Results:
- Estimated NO2 partition coefficient between n-octanol and water is 2.7.
- Estimated NO2 partition coefficient between lipid membranes and water is 1.5, indicating moderate hydrophobicity.
- Estimated NO2 permeability coefficient is 5 cm/s, significantly higher than peroxynitrous acid.
Conclusions:
- Lipid membranes are not significant barriers to nitrogen dioxide (NO2) transport.
- NO2 exhibits moderate hydrophobicity, facilitating its passage through biological membranes.
- Findings contribute to understanding NO2's biological and environmental impact at the cellular level.
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