Why folates self-assemble: a simulation-based study

Abstract

Folates (and other chromonics molecules) have been shown to self-assemble into ordered structures even at low concentrations. In this study, simulations are used to first replicate the self-assembly of folates and understand why folic acid does not assemble while folate ions do. Subsequently, these simulations replicate the change in structure and behaviour of the assembly with increasing concentration of folates, comparing them to experimental observations in earlier studies. The study then uses fictitious molecules and ions to understand which components of the folate ions drive, or otherwise affect, assembly of the folates and to abstract some guiding principles about structure of chromonics molecules and the impact on assembly. This study shows that while the aromatic rings drive stacking, the hydrophilic groups help solvate and hence control the order of the aromatic stacks, and the 1-ring-diacid moiety controls the orientation of the ions in their plane.

Keywords::

• self-assembly
• folates
• aromatic interactions
• simulations
• molecular dynamics

Acknowledgements

The authors acknowledge support from Indian Institute of Technology, Delhi as well as from Department of Science and Technology, Government of India, for this work.