Effect of graphene oxide on the conformational transitions of amyloid beta peptide: A molecular dynamics simulation study.
The interactions between nanomaterials (NMs) and amyloid proteins are central to the nanotechnology-based diagnostics and therapy in neurodegenerative disorders such as Alzheimer's and Parkinson's. Graphene oxide (GO) and its derivatives have shown to modulate the aggregation pattern of disease causing amyloid beta (Aβ) peptide. However, the mechanism is still not well understood. Using molecular dynamics simulations, the effect of graphene oxide (GO) and reduced graphene oxide (rGO) having carbon:oxygen ratio of 4:1 and 10:1, respectively, on the conformational transitions (alpha-helix to beta-sheet) and the dynamics of the peptide was investigated. GO and rGO decreased the beta-strand propensity of amino acid residues in Aβ. The peptide displayed different modes of adsorption on GO and rGO. The adsorption on GO was dominated by electrostatic interactions, whereas on rGO, both van der Waals and electrostatic interactions contributed in the adsorption of the peptide. Our study revealed that the slight increase in the hydrophobic patches on rGO made it more effective inhibitor of conformational transitions in the peptide. Alpha helix-beta sheet transition in Aβ peptide could be one of the plausible mechanism by which graphene oxide may inhibit amyloid fibrillation.
Institute of Life Sciences, School of Science and Technology, Ahmedabad University, University Road, Ahmedabad 380009, Gujarat, India; Academy of Scientific and Innovative Research, Anusandhan Bhavan, 2 Rafi Marg, New Delhi 110001, India; CSIR-Indian Institute of Toxicology Research, Mahatma Gandhi Road, P.O. Box. 80, Lucknow 226001, Uttar Pradesh, India.
Lokesh
L
Baweja
CSIR-Central Leather Research Institute, Sardar Patel Road, Adyar, Chennai 600020, Tamil Nadu, India.
Kanagasabai
K
Balamurugan
Academy of Scientific and Innovative Research, Anusandhan Bhavan, 2 Rafi Marg, New Delhi 110001, India; CSIR-Central Leather Research Institute, Sardar Patel Road, Adyar, Chennai 600020, Tamil Nadu, India.
Venkatesan
V
Subramanian
Academy of Scientific and Innovative Research, Anusandhan Bhavan, 2 Rafi Marg, New Delhi 110001, India; CSIR-Indian Institute of Toxicology Research, Mahatma Gandhi Road, P.O. Box. 80, Lucknow 226001, Uttar Pradesh, India. Electronic address: alokdhawan@iitr.res.in.
Alok
A
Dhawan
D000327:Adsorption; D000595:Amino Acid Sequence; D016229:Amyloid beta-Peptides / Q000037:antagonists & inhibitors* / Q000737:chemistry; D001665:Binding Sites; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D010446:Peptide Fragments / Q000037:antagonists & inhibitors* / Q000737:chemistry; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D055672:Static Electricity; D040681:Structural Homology, Protein; D013499:Surface Properties; D013816:Thermodynamics
D016229:Amyloid beta-Peptides; D010087:Oxides; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); D006108:Graphite
Amyloid beta peptide; Graphene oxide; Molecular dynamics simulation; Nanomaterials; Neurodegenerative disorders