Taylor A. Dorlus - Clark Atlanta University
Co-Author(s): Dalia Daggag and Tandabany Dinadayalane, Clark Atlanta University, Atlanta, GA
Our computational study based on density functional theory (DFT) calculations is focused to understand the binding of two amino acids (Histidine and Proline) individually with the graphene sheet. Two finite size graphene sheets of 62 and 186 carbon atoms were considered in this study. The edges of these two graphene sheets were terminated with hydrogen atoms. We have performed the conformational analysis for those two amino acids using MMFF force field implemented in Spartan ’14. We took two lowest energy conformers and one least stable conformer for optimization at the DFT level and to build the complexes with two different sizes of the graphene sheets. For each of the conformer of the amino acids, different possible orientations were taken into account in building the complexes. All of the complexes were fully optimized using M06-2X/6-31G(d) level using Gaussian 09 program package. The detailed study of the interactions of amino acids with graphene will provide the knowledge required for graphene-based biological/biocompatible applications such as biochemical sensors. Binding energies with and without basis set superposition error (BSSE) were calculated. Our aim is to understand the binding affinity of histidine and proline with the graphene, and the effect of varying the graphene sheet on the binding affinity. In case of histidine-graphene complex, the competition between pi-pi and C-H/N-H…pi interactions exist. However, the proline-graphene complexes are stabilized by C-H…pi and N-H…pi interactions.
Funder Acknowledgement(s): TD acknowledges the National Science Foundation (NSF) for the funding through HBCU-UP Research Initiation Award (Grant number 1601071). DD acknowledges Saudi Arabian Cultural Mission (SACM) for the fellowship. We acknowledge the Extreme Science and Engineering Discovery Environment (XSEDE) for the computational resources.
Faculty Advisor: Tandabany Dinadayalane, email@example.com
Role: Conformational analysis of histidine and proline. Building of all the complexes and the calculations to find the binding energies.