Paola M. Urbaez - Clark Atlanta University
Co-Author(s): Jovian Lazare and Tandabany Dinadayalane, Clark Atlanta University, Atlanta, GA
In this study, density functional theory (DFT) calculations utilizing M06-2X/6-31G^* level were performed to understand the binding of two aliphatic alpha-amino acids (Alanine and Valine) individually with the graphene sheet. Graphene sheets comprising of 62 and 186 carbon atoms with their edges terminated by hydrogen atoms were considered for our investigation. We have performed the conformational analysis for those two amino acids initially using MMFF force field implemented in Spartan ’14. All the geometries of the conformers obtained were refined at the HF/6-31G(d) level in order to find the top two most stable conformers and one least stable conformer for each of the two amino acids. The selected three conformers for alanine and valine are used to build the complexes with two different sizes of the graphene sheets. For each of the conformer of alanine and valine, different possible orientations were considered in building the complexes. All of the complexes were fully optimized using M06-2X/6-31G(d) level. The data from this computational study of the binding of aliphatic amino acids with graphene will provide the knowledge helpful for experimentalists to build graphene-based biological/biocompatible materials. Binding energies with and without basis set superposition error (BSSE) were calculated. We examined the correlation between the intermolecular distance and the binding affinity. Our aim is to understand how the binding affinity of these two amino acids varies by changing the size of graphene, and the factors controlling the stability of the complexes.
Funder Acknowledgement(s): TD acknowledges the National Science Foundation (NSF) for the funding through HBCU-UP Research Initiation Award (Grant number 1601071). We acknowledge the Extreme Science and Engineering Discovery Environment (XSEDE) for the computational resources.
Faculty Advisor: Tandabany Dinadayalane, firstname.lastname@example.org
Role: Conformational analysis of the two amino acids, building of all the complexes and completing all the calculations at the DFT level.