title: Electromagnetic-field effects on structure and dynamics of amyloidogenic peptides.
abstract: Electromagnetic fields (EMFs) are ever-present, and so is the need to better understand their influence on human health and biological matter in general. The interaction between a molecular system and external EMF can alter the structure, and dynamical behaviour, and, hence, biological function of proteins with uncertain health consequences. This urges a detailed investigation of EMF-induced effects on basic protein biophysics. Here, we used all-atom non-equilibrium molecular dynamics simulations to understand and quantify the response mechanisms of the amyloidogenic apoC-II(60-70) peptides to non-ionising radiation by modelling their behaviour under external electromagnetic and electric fields of different strengths. Our simulations show high strength fields (>0.04 V/nm) cause structural changes in apoC-II(60-70) due to the peptide dipole alignment along the applied field direction, which disrupts the inherent β-hairpin conformation known to be the intermediate state for fibril formation. The intermediate field-strength range (0.04-0.004 V/nm) causes a significant acceleration in peptide dynamics, which leads to the increased population of structures with fibril-inhibiting characteristics, such as the separated N- and C-termini and colocation of the aromatic residues at the same peptide face. In contrast, lower field strengths (<0.004 V/nm) promote the formation of the amyloid-prone hairpin structures relative to the ambient conditions. These findings suggest that intermediate-strength electromagnetic fields could be considered for designing alternative treatments of amyloid diseases, while the very high and low field strengths could be employed for engineering well-ordered fibrillar aggregates for non-medicinal applications.
authors.affiliation: School of Engineering, RMIT University, G.P.O. Box 2476, Melbourne, Australia.
authors.forename: Nevena
authors.initials: N
authors.lastname: Todorova
authors.affiliation: School of Engineering, RMIT University, G.P.O. Box 2476, Melbourne, Australia.
authors.forename: Alan
authors.initials: A
authors.lastname: Bentvelzen
authors.affiliation: School of Chemical & Bioprocess Engineering, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Niall J
authors.initials: NJ
authors.lastname: English
authors.affiliation: School of Engineering, RMIT University, G.P.O. Box 2476, Melbourne, Australia.
authors.forename: Irene
authors.initials: I
authors.lastname: Yarovsky
mesh_terms: D000682:Amyloid / Q000737:chemistry*; D053304:Apolipoprotein C-II / Q000737:chemistry*; D004574:Electromagnetic Fields; D056004:Molecular Dynamics Simulation; D011487:Protein Conformation
chemical_list: D000682:Amyloid; D053304:Apolipoprotein C-II