Assessing SIRAH's Capability to Simulate Intrinsically Disordered Proteins and Peptides

We explored the dynamics of α-synuclein (randomly generated conformers), p31-43(PDB is: 6QAX), PaaA2 antitoxin (PDB id:3ZBE), Amyloid-beta 1-40 (PDB id: 2FLM), and Insulin C-peptide (PDB id: 1T0C) using the SIRAH force field running with the Gromacs 18.4 under the conditions reported in Machado et al. JCTC 2019, adding 150 mM NaCl according to Machado & Pantano JCTC 2020.

Briefly, simulations were performed in triplicate for 5 μs at 300 K and 1 atm in the NPT ensemble. We used a time-step of 20 fs, a direct cutoff for non-bonded interactions of 1.2 nm, and Particle Mesh Ewald summation for long-range electrostatics. For α-synuclein and p31-43, initial conformations were obtained from models built on arbitrary conformations and heated up to 340 K. For PaaA2 antitoxin, Amyloid-beta 1-40, and Proinsulin C-peptide, three different NMR conformers were arbitrarily selected.