title: Hydrotalcite Intercalated siRNA: Computational Characterization of the Interlayer Environment.
abstract: Using molecular dynamics (MD) simulations, we explore the structural and dynamical properties of siRNA within the intercalated environment of a Mg:Al 2:1 Layered Double Hydroxide (LDH) nanoparticle. An ab initio force field (Condensed-phase Optimized Molecular Potentials for Atomistic Simulation Studies: COMPASS) is used for the MD simulations of the hybrid organic-inorganic systems. The structure, arrangement, mobility, close contacts and hydrogen bonds associated with the intercalated RNA are examined and contrasted with those of the isolated RNA. Computed powder X-ray diffraction patterns are also compared with related LDH-DNA experiments. As a method of probing whether the intercalated environment approximates the crystalline or rather the aqueous state, we explore the stability of the principle parameters (e.g., the major groove width) that differentiate both A- and A'- crystalline forms of siRNA and contrast this with recent findings for the same siRNA simulated in water. We find the crystalline forms remain structurally distinct when intercalated, whereas this is not the case in water. Implications for the stability of hybrid LDH-RNA systems are discussed.
authors.affiliation: Centre for Computational Molecular Science, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Qld 4072, Brisbane, Australia. smithsc@ornl.gov.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.forename: Defang
authors.initials: D
authors.lastname: Ouyang
authors.forename: Vinuthaa
authors.initials: V
authors.lastname: Murthy
authors.forename: Yunyi
authors.initials: Y
authors.lastname: Wong
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Xu
authors.forename: Sean C
authors.initials: SC
authors.lastname: Smith