Effect of Disulfide Bonds in Antifungal Peptide from Petunia Hybrida: A Molecular Dynamics Study

Abstract

The solution structure of a novel plant defensin (PhD1) contains a fifth disulfide bond, unlike other plant defensins, which have four disulfide bonds. The present study aims to better understand the stability, thermal dependence and the role of disulfide bonds in the tertiary structure of PhD1 using Molecular Dynamics (MD) simulations. The secondary structures are intact in the native structure simulated at 300 K. However, in the mutant structures a small variation is observed. A significant shift in the peptide conformation is observed when the additional fifth disulfide bond (Cys7-Cys23) is mutated. No large change in the tertiary structure conformation is observed till 400 K, which demonstrates the high thermal stability of the protein. Here, we also show that the mutation of disulfide bonds did not result in a drastic conformational change. The antifungal property along with high structural stability of the plant defensin protein makes it a promising candidate for the development of novel fungicides.

From Anna University to America to Agriculture

“…My association as Associate Editor,BMC Bioinformatics (a UK based Biomed Central publication since 2005) was judicious. Serving as advisors to several students leading to the award of the PhD degree by Research in the field is often sensitive [ 60 - 62 ]. My research contributions in Biotechnology and Bioinformatics include that of lipase engineering, vaccine science, genome design, protein-protein interactions and interfaces cholera toxins is a lifetime experience with enthusiasm.…”

Analysis of mutations of defensin protein using accelerated molecular dynamics simulations

“…Molecular dynamics (MD) technique has emerged as an increasingly prevalent tool that can be used to analyze the atomic movement and flexibility in proteins, peptide protein-ligands, and protein-DNA complexes within a box filled with water and ions [28][29][30]. Recently, the effect of a disulfide bond present in an antifungal peptide derived from Petunia Hybrida was analyzed using 5 ns MD simulations [31]. To investigate the role of mutations in the RsAFP2 in increasing peptide stability, we performed accelerated Molecular Dynamics (aMD) simulations in water and lipid bilayer.…”