Computational Insights for interactions between NsP2 and NsP3 of CHIKV and Hormones through DFT computations and Molecular Dynamics Simulations.

The non-structural protein (nsP2 & nsP3) of the CHIKV is responsible for the transmission of viral infection. The main role of nsp is involved in the transcription process at an early stage of the infection. In this work, authors have studied the impact of nsP2 and nsP3 of CHIKV on hormones present in the human body using a computational approach. The ten hormones of chemical properties such as 4-Androsterone-2,17-dione, aldosterone, androsterone, corticosterone, cortisol, cortisone, estradiol, estrone, progesterone and testosterone were taken as a potency. From the molecular docking, the binding energy of the complexes is estimated, and cortisone was found to be the highest negative binding energy (-6.57 kcal/mol) with the nsP2 protease and corticosterone with the nsP3 protease (-6.47 kcal/mol). This is based on the interactions between hormones and NsP2/NsP3, which are types of noncovalent intermolecular interactions categorized into three types: electrostatic interactions, van der Waals interactions, and hydrogen-bonding. To validate the docking results, molecular dynamics simulations and MM-GBSA methods were performed. The change in enthalpy, entropy, and free energy were calculated using MM-GBSA methods. The nsP2 and nsP3 protease of CHIKV interact strongly with the cortisone and corticosterone with free energy changes of -20.55 & -36.08 kcal/mol, respectively.

Significant Increase in the Dipole Moment of Graphene on Functionalization: DFT Calculations and Molecular Dynamics Simulations.

The limited solubility of graphene in water can be attributed to the existence of π-π bonds connecting its layers. Functionalized graphene or graphene oxide (GO) is frequently produced in order to overcome the shortcomings of graphene. Using density functional theory (DFT) calculation, functionalized graphene with various combinations of hydroxyl, epoxy, and carboxylic functional groups were investigated computationally. The study focused on the effects of functional group combinations on the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies, giving information about the chemical reactivity and stability of the molecules under investigation. Global chemical reactivity descriptors, including chemical hardness, softness, electronegativity, chemical potential, and electrophilicity index, were calculated to further elucidate the overall stability and reactivity of the molecules. The results demonstrated that the introduction of oxygen-containing functional groups on graphene significantly influenced its electronic properties, leading to variations in the chemical reactivity and stability. Molecular electrostatic potential (MEP) maps highlighted the susceptibility of specific regions to electrophilic and nucleophilic attacks. The flexibility and stability of functionalized graphene through root mean square fluctuation (RMSF) and root mean square deviation (RMSD) analyses indicate the stability of functionalized graphene in water. This comprehensive computational investigation provides valuable insights into the design and understanding of functionalized graphene for potential applications in drug delivery.