A Molecular Dynamics Study of Lunasin

Abstract

Lunasin, a 43 amino acid peptide, suppresses chemically induced transformations in mammalian cells and skin carcinogenesis in mice. This peptide has also been reported to exhibit very good bioavailability after its oral administration. However, despite its biological and medicinal significance, the exact three-dimensional (3D) structure of lunasin is thus far not yet fully characterized. Thus this work is aimed at exploring the conformational profile of lunasin,using classical molecular dynamics (MD) simulations at the time scale of 300 ns. The results obtained from the MD trajectory reveal that lunasin has a strong propensity to exhibit three characteristic α helical bundles in its structure supported by residues His⁵-Cys¹⁰, Cys²²-Ile³⁰ and Asp³⁵-Asp⁴¹. The reported cell adhesion motif (Arg-Gly-Asp) of lunasin responsible for its binding to cell chromatin, on other hand, did not exhibit any characteristic secondary feature. The structural information obtained from the current study could be useful to better understand the bioactive conformation of lunasin.

Keywords: Lunasin, molecular dynamics, amber, CLASICO, α-helix, β-turn, PTRAJ, RGD, RMSD