3D Columnar Phase of Stacked Short DNA Organized by Coherent Membrane Undulations.
Langmuir
; 35(36): 11891-11901, 2019 09 10.
Article
en En
| MEDLINE
| ID: mdl-31408350
ABSTRACT
We report on the discovery of a new organized lipid-nucleic acid phase upon intercalation of blunt duplexes of short DNA (sDNA) within cationic multilayer fluid membranes. End-to-end interactions between sDNA leads to columnar stacks. At high membrane charge density, with the inter-sDNA column spacing (dsDNA) comparable but larger than the diameter of sDNA, a 2D columnar phase (i.e., a 2D smectic) is found similar to the phase in cationic liposome-DNA complexes with long lambda-phage DNA. Remarkably, with increasing dsDNA as the membrane charge density is lowered, a transition is observed to a 3D columnar phase of stacked sDNA. This occurs even though direct DNA-DNA electrostatic interactions across layers are screened by diffusing cationic lipids near the phosphate groups of sDNA. Softening of the membrane bending rigidity (κ), which further promotes membrane undulations, significantly enhances the 3D columnar phase. These observations are consistent with a model by Schiessel and Aranda-Espinoza where local membrane undulations, due to electrostatically induced membrane wrapping around sDNA columns, phase lock from layer-to-layer, thereby precipitating coherent "crystal-like" undulations coupled to sDNA columns with long-range position and orientation order. The finding that this new phase is stable at large dsDNA and enhanced with decreasing κ is further supportive of the model where the elastic cost of membrane deformation per unit area around sDNA columns (â κh2/dsDNA4, h2 = sum of square of amplitudes of the inner and outer monolayer undulations) is strongly reduced relative to the favorable electrostatic attractions of partially wrapped membrane around sDNA columns. The findings have broad implications in the design of membrane-mediated assembly of functional nanoparticles in 3D.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fosfatidilcolinas
/
ADN
/
Ácidos Grasos Monoinsaturados
/
Compuestos de Amonio Cuaternario
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Langmuir
Asunto de la revista:
QUIMICA
Año:
2019
Tipo del documento:
Article
País de afiliación:
Estados Unidos