Poster Presentation Melbourne Protein Group Student Symposium 2013

Interactions of bioactive peptides with nanogold: Insights from theoretical simulations (#19)

Patrick Charchar 1 , Nevena Todorova 1 , Heiko Andresen 2 , Yiyang Lin 2 , Molly M Stevens 2 , Irene Yarovsky 1
  1. Health Innovations Research Institute; School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Melbourne, VIC, Australia
  2. Department of Materials and Bioengineering, Imperial College London, London, United Kingdom

Being able to accurately identify and quantify the presence of specific biomolecules circulating in serum and other bodily fluids, is crucial in helping correctly diagnose many diseases. As a result, a vast amount of research has recently been dedicated to developing novel biosensors with improved sensitivity, speed and cost efficiency, compared to conventional methods. The past decade has seen the advancement of many exciting and innovative sensors through the utilisation of gold nanoparticles’ (AuNPs) unique physical, chemical and optical properties.1-3 By pairing these interesting qualities with the ability to be easily functionalised with chemically discriminatory ligands, AuNP-based sensors have been shown to be excellent candidates for the specific detection of a variety of biomolecular targets.4-8

Although much experimental6-9 and theoretical10-13 advancement has been made in this field, further exploration of the conformational and molecular interactions involved at the peptide-gold, peptide-solvent and peptide-peptide interfaces is required to correctly understand these systems. The work presented herein is in collaboration with an experimental team at Imperial College London,6,7 and offers an atomistic insight into these interactions through classical molecular dynamics simulations of various bioresponsive synthetic peptide-AuNP complexes.

Our results illustrate that peptide flexibility, mobility, and conformational preference are strongly influenced by peptide-peptide interactions and are intimately related to amino acid composition and location within the peptide sequence. We find that particular residues are attributed to driving adsorption onto gold surfaces, while in contrast others are responsible for discouraging peptide-gold contact. Solvent interactions with the complexes are also investigated and observed to aid the assemblies’ stability and help balance electrostatics. The findings of our research helps to develop new knowledge about the molecular interactions at the nano-bio interface, which can be exploited for improved molecular recognition needed in biosensors and future synthesis approaches.

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