# Protein molecular dynamics simulation Prepare a protein, run conventional GROMACS molecular dynamics, and retain trajectories, energies, settings, and structural analyses. [Open simulation workflow](https://proteiniq.io/app/workflows/templates?template=protein-molecular-dynamics-simulation)[Contact sales](https://proteiniq.io/contact) ## More molecular dynamics simulation workflows ## Tools for protein molecular dynamics simulation Use these methods to prepare inputs, run the core analysis, inspect outputs, and validate the evidence described in this workflow. [![GROMACS](https://proteiniq.io/_next/image?url=%2Fimages%2Ftools%2Fgmx-mmpbsa.webp&w=96&q=75&dpl=dpl_J8tu6aF3F41kEvMFgYtuMXes1ynJ) ### GROMACS Run conventional protein molecular dynamics with classical force fields](https://proteiniq.io/app/gromacs)[![PDBFixer](https://proteiniq.io/_next/image?url=%2Fimages%2Ftools%2Fpdb-fixer-featured.webp&w=96&q=75&dpl=dpl_J8tu6aF3F41kEvMFgYtuMXes1ynJ) ### PDBFixer Repair missing atoms and standardize structures before simulation](https://proteiniq.io/app/pdb-fixer)[![MD Trajectory Analysis](https://proteiniq.io/_next/image?url=%2Fimages%2Ftools%2Fmd-trajectory-analysis.webp&w=96&q=75&dpl=dpl_J8tu6aF3F41kEvMFgYtuMXes1ynJ) ### MD Trajectory Analysis Analyze compatible trajectories with structural and dynamical metrics](https://proteiniq.io/app/md-trajectory-analysis)[![OpenMM](https://proteiniq.io/_next/image?url=%2Fimages%2Ftools%2Fopenmm.webp&w=96&q=75&dpl=dpl_J8tu6aF3F41kEvMFgYtuMXes1ynJ) ### OpenMM Run GPU-accelerated all-atom protein or protein–ligand simulations](https://proteiniq.io/app/openmm)[![PDB2PQR](https://proteiniq.io/_next/image?url=%2Fimages%2Ftools%2Fpdb2pqr.webp&w=96&q=75&dpl=dpl_J8tu6aF3F41kEvMFgYtuMXes1ynJ) ### PDB2PQR Prepare protonation, charges, and radii for structural review](https://proteiniq.io/app/pdb2pqr)[![PROPKA 3](https://proteiniq.io/_next/image?url=%2Fimages%2Ftools%2Fpropka-3.webp&w=96&q=75&dpl=dpl_J8tu6aF3F41kEvMFgYtuMXes1ynJ) ### PROPKA 3 Estimate pKa values and inspect protonation-sensitive sites](https://proteiniq.io/app/propka)[![RMSD calculator](https://proteiniq.io/_next/image?url=%2Fimages%2Ftools%2Frmsd-calculator.webp&w=96&q=75&dpl=dpl_J8tu6aF3F41kEvMFgYtuMXes1ynJ) ### RMSD calculator Compare representative structures with RMSD](https://proteiniq.io/app/rmsd-calculator)[![Radius of gyration](https://proteiniq.io/_next/image?url=%2Fimages%2Ftools%2Fradius-of-gyration.webp&w=96&q=75&dpl=dpl_J8tu6aF3F41kEvMFgYtuMXes1ynJ) ### Radius of gyration Measure compactness for representative structures](https://proteiniq.io/app/radius-of-gyration)[![DSSP](https://proteiniq.io/_next/image?url=%2Fimages%2Ftools%2Fdssp.webp&w=96&q=75&dpl=dpl_J8tu6aF3F41kEvMFgYtuMXes1ynJ) ### DSSP Assign secondary structure to representative protein conformations](https://proteiniq.io/app/dssp)[![SASA calculator](https://proteiniq.io/_next/image?url=%2Fimages%2Ftools%2Fsasa-calculator.webp&w=96&q=75&dpl=dpl_J8tu6aF3F41kEvMFgYtuMXes1ynJ) ### SASA calculator Calculate solvent-accessible surface area for exported structures](https://proteiniq.io/app/sasa-calculator)[![MolProbity](https://proteiniq.io/_next/image?url=%2Fimages%2Ftools%2Fmolprobity.webp&w=96&q=75&dpl=dpl_J8tu6aF3F41kEvMFgYtuMXes1ynJ) ### MolProbity Validate representative protein conformations](https://proteiniq.io/app/molprobity)[![pyRMSD](https://proteiniq.io/_next/image?url=%2Fimages%2Ftools%2Fpyrmsd.webp&w=96&q=75&dpl=dpl_J8tu6aF3F41kEvMFgYtuMXes1ynJ) ### pyRMSD Calculate pairwise RMSD matrices for exported structure ensembles](https://proteiniq.io/app/pyrmsd) ## What is protein molecular dynamics simulation? Protein [molecular dynamics simulation](https://proteiniq.io/use-cases/molecular-dynamics-simulation) is a computer method that calculates how the atoms in a parameterized protein system move over time. It integrates equations of motion to generate a time-ordered trajectory that can test structural stability, flexibility, interactions, and conformational hypotheses, but the result reflects the chosen force field, solvent, protonation, boundaries, ensemble, starting state, and accessible timescale. Begin with a structure whose biological assembly, chain boundaries, missing residues, ligands, cofactors, mutations, and protonation states match the question. Preparation choices can alter the trajectory more than later plotting choices, so inspect the simulation-ready model directly. ProteinIQ can run conventional protein MD with [GROMACS](https://proteiniq.io/app/gromacs) and return trajectory, energy, topology, final-structure, analysis, and archive files. Current runs cover 1–200 ns. Use independent replicates and convergence-aware analysis when the conclusion depends on an ensemble rather than a simple pipeline check. ### When to use protein molecular dynamics simulation - Protein stability, flexibility, mutation effects, and conformational hypotheses - A prepared protein structure, force-field choice, solvent and ion conditions, duration, and replicate plan ### Strengths and limitations A conventional GROMACS or [OpenMM](https://proteiniq.io/app/openmm) run can connect a prepared protein structure to trajectories, energies, and contact analyses in one reproducible workflow. Independent starts help assess whether local motions are robust. Finite trajectories can miss slow transitions, while force fields and solvent models approximate the physical system. Missing regions, cofactors, protonation, and initial conformation can change the result; report preparation and protocol alongside any stability claim. ## Protein molecular dynamics simulation methods GROMACS uses classical force fields to calculate bonded and nonbonded interactions, integrates motion at femtosecond-scale timesteps, and applies thermostat, barostat, electrostatics, and constraint settings defined by the run protocol. A production trajectory should follow documented minimization and equilibration. Temperature and pressure traces alone do not establish structural equilibration; inspect slow observables and compare independent segments or replicas. ## Protein molecular dynamics simulation applications Protein molecular dynamics simulation is best suited to protein stability, flexibility, mutation effects, and conformational hypotheses. Match the modeled system, timescale, resolution, and ensemble to the observable rather than choosing a protocol because it produces a longer trajectory or more elaborate figure. Use simulation as model-based evidence. Connect trajectory observations to experimental data, alternative parameterizations, independent starts, and uncertainty whenever the downstream claim concerns mechanism, affinity, kinetics, stability, or population. ## How to run protein molecular dynamics simulation online The connected workflow prepares the structure and runs the configured conventional simulation. Review every system and ensemble setting before submission. 1. **Inspect structure.** Verify biological assembly, chains, missing regions, alternate locations, cofactors, and protonation-sensitive sites. 2. **Prepare system.** Repair only justified defects and preserve both the original and prepared coordinates. 3. **Configure GROMACS.** Set force field, solvent, temperature, pressure, ionic strength, duration, and output interval. 4. **Run simulation.** Run minimization, equilibration, and production while retaining logs, energies, topology, and trajectory. 5. **Analyze ensemble.** Review equilibration, stability, flexibility, contacts, convergence, and replicate agreement. ## How to interpret protein molecular dynamics simulation results Read RMSD with the alignment selection and reference, RMSF with residue coverage, [radius of gyration](https://proteiniq.io/app/radius-of-gyration) with domain motion, and contact metrics with periodic-boundary treatment. Plateau language should be supported by blockwise behavior, not visual impression alone. Separate observations from claims. A stable trajectory supports consistency with the modeled state over the sampled interval; it does not prove experimental stability, binding affinity, catalytic activity, or exhaustive sampling. ## How protein molecular dynamics simulation works Fetch or upload a protein structure, repair it with PDB Fixer, and run a conventional GROMACS protein simulation. 1. **Inspect structure.** Verify biological assembly, chains, missing regions, alternate locations, cofactors, and protonation-sensitive sites. 2. **Prepare system.** Repair only justified defects and preserve both the original and prepared coordinates. 3. **Configure GROMACS.** Set force field, solvent, temperature, pressure, ionic strength, duration, and output interval. 4. **Run simulation.** Run minimization, equilibration, and production while retaining logs, energies, topology, and trajectory. 5. **Analyze ensemble.** Review equilibration, stability, flexibility, contacts, convergence, and replicate agreement. ## Inputs and outputs Check formats before running, then inspect and download the result from every workflow step. ### Inputs #### Simulation evidence `PDB``mmCIF``TPR``GRO``XTC` A protein PDB, ENT, or mmCIF structure with defined system conditions and simulation settings. ### Outputs #### Simulation outputs `XTC``PDB``CSV``JSON``ZIP` PDB, XTC, EDR, TPR, CSV analyses, logs, and a downloadable simulation archive. ## Frequently asked questions AI answers from our docs. 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