
Predict pKa values of ionizable groups in proteins and protein-ligand complexes from 3D structure. PROPKA calculates environment-driven pKa shifts for standard ionizable residues, terminal groups, and supported ligand atom types.

Compute 200+ RDKit molecular descriptors, drug-likeness rule violations, and structural fingerprints for QSAR, virtual screening, and ML workflows

Predict metal and water binding sites in protein structures using 3D convolutional neural networks (AllMetal3D + Water3D).

Plot net charge vs pH for protein sequences. Visualize how protein charge changes across pH 0-14 and identify the isoelectric point (pI) where the net charge crosses zero.

Match experimental peptide masses against theoretical digest fragments of a protein sequence. Identify peptides from mass spectrometry data by peptide mass fingerprinting.

Generate Kyte-Doolittle hydropathy plots to visualize hydrophobic and hydrophilic regions along protein sequences. Identify transmembrane domains and surface-exposed regions.

Generate hydrophobicity plots using 24 different amino acid scales. Visualize hydrophobic and hydrophilic regions for protein analysis, epitope prediction, and membrane protein studies.

Predict protease and chemical cleavage sites across a protein sequence for up to 39 enzymes simultaneously. Identify where each enzyme cuts, the cleavage residue, and context window around each site.

Cleave a protein sequence with a chosen protease and compute the masses of the resulting peptides. Supports multiple enzymes, missed cleavages, chemical modifications, and different ion types for mass spectrometry experiment planning.

Calculate protein parameters, including molecular weight, theoretical pI, extinction coefficients, aromaticity, secondary structure fractions, atomic composition, estimated half-life, and several indices, including instability, aliphatic index, and GRAVY.
Aggrescan3D (A3D) estimates residue-level aggregation propensity from a protein structure. Unlike sequence-only predictors, it evaluates each residue in its three-dimensional context by combining the intrinsic AGGRESCAN scale with solvent exposure and nearby residues in space.
This ProteinIQ tool runs the static native Aggrescan3D workflow on a single PDB structure per job. The goal is to support the original static analysis outputs faithfully rather than approximate them with local scoring logic.
The native static pipeline performs three core steps:
freeSASA.The 10 Å threshold is the default patch-oriented analysis mode in Aggrescan3D. The 5 Å setting narrows the calculation toward more local residue contributions.
| Input | Description |
|---|---|
Protein Structure | One PDB structure uploaded as .pdb or .ent, or fetched from RCSB by PDB ID. Only one structure is accepted per job. |
| Setting | Description |
|---|---|
Distance threshold | Spatial radius used by the native static calculation. 10 Å is the default patch mode. 5 Å emphasizes more local residue contributions. |
The tool returns native static outputs directly:
A3D.csvA3D.csv, A3D_summary.json, output.pdb, and native plot imagesA3D_summary.json| Output column | Description |
|---|---|
Protein | Structure identifier used for the run |
Chain | Chain identifier |
Residue | Residue number |
Residue Name | One-letter residue code |
Score | native Aggrescan3D residue score |
More positive scores indicate residues in structural environments that are more aggregation-prone. More negative scores indicate residues in environments that promote solubility. The scored PDB file can be opened in molecular viewers for structure-based inspection, while the summary JSON provides per-chain and global score statistics from the published workflow.