Molecular Docking Studies on The Binding Interaction and Stability of Ovalbumin with 4-Dicyanomethylene-2,6-Dimethyl-4H-Pyran (DDPYRA) Dye in the Presence of Flavonoids

Abstract

Introduction: Molecular docking (MOD) techniques were employed in establishing the binding affinity and stability of Ovalbumin (OVA) with 4-Dicyanomethylene-2,6-Dimethyl-4-H-pyran (DDPYRA) dye in the presence of various flavonoids derived from Psidium guajava. OVA, a globular protein serves as the host, and DDPYRA acts as the guest.

Objectives: Flavonoids as competing guest molecule was docked simultaneously to establish the affinity of host-guest complex based on the stability and molecular interactions. The various dye-OVA conformers   differ in energetics and molecular interactions, are compared with that of dye-OVA-flavonoids complex.

Methods: MOD is utilised as an effective tool and non-evasive technique for determining the stability of guest (dye)/competing guest (Flavonoids) with host (protein) is provided in depth.

Results: Docking studies reveal that the complexes of OVA-flavonoids and OVA-DDPYRA complexes are energetically less stable compared to that of OVA-DDPYRA-flavonoids complex. The binding stability is attributed to several conventional hydrogen-bonding (cHB) interactions existing between the amino acid (AA) residues of OVA with flavonoids. DDPYRA predominantly acts as hydrogen-bonding (HB) acceptor, and the protein as the donor. HB interactions predominate over hydrophobic interactions in the OVA-DDPYRA- flavonoids complex. Docking of flavonoids to the OVA-DDPYRA complex enhances the binding stability.

Conclusions: MOD studies further elucidate that dye is bound to several AA residues through cHB and non-conventional hydrogen-bonding (NcHB) interactions accompanied by hydrophobic interactions and weak van der Waals forces such that the introduction of flavonoids promotes more number of bimolecular interactions.