Resolved chemical identity

CYSTEINESULFONIC ACID

Identity / evidence review pending

complete_deposited_InChIKey

0 assay / association records0 preparations0 research-ligand PDB entries

No deposited PWWP research-ligand geometry is classified for this preparation in the selected release. Deposition of a buffer/ion is not binding evidence.

Clinical / development status: Not independently curated. A chemical probe classification does not imply medicinal approval.

Identity is separate from preparation

Chemical identity

Stable identity: INCHIKEY:XVOYSCVBGLVSOL-REOHCLBHSA-N
Full InChIKey: XVOYSCVBGLVSOL-REOHCLBHSA-N
Source identity status: complete deposited InChIKey
Deposited CCD identifiers: OCS
External identifiers: See deposited identity and source links

Reference formula: C3H7NO5S
Calculated molecular weight: 169.158
Calculated descriptors: cLogP -1.7139 · TPSA 117.69 Å² · HBD 3 · HBA 4RDKit 2025.09.3; calculations for this source identity, not experimental measurements.
Depiction validation: verified smiles full inchikey match

SMILES, InChI & complete identity record

Isomeric SMILES: C([C@@H](C(=O)O)N)S(=O)(=O)O
InChI: Not curated

{
  "aliases": [
    "CYSTEINESULFONIC ACID"
  ],
  "ccd_ids": [
    "OCS"
  ],
  "ccd_names": "[\"CYSTEINESULFONIC ACID\"]",
  "ccd_types": "[\"L-peptide linking\"]",
  "chemical_id": "INCHIKEY:XVOYSCVBGLVSOL-REOHCLBHSA-N",
  "connectivity_block": "XVOYSCVBGLVSOL",
  "curated_source_sha256": null,
  "curation_version": "frozen-v1.2",
  "external_identifiers": {},
  "formal_charge_by_ccd": "{\"OCS\": 0}",
  "formulae": "[\"C3 H7 N O5 S\"]",
  "geometry_note": "CCD ideal SDF is a reference chemical geometry, not a deposited bound pose.",
  "identity_status": "complete_deposited_InChIKey",
  "inchikey": "XVOYSCVBGLVSOL-REOHCLBHSA-N",
  "inventory_origin": "v1_CCD_inventory",
  "isomeric_smiles": "C([C@@H](C(=O)O)N)S(=O)(=O)O",
  "primary_name": "CYSTEINESULFONIC ACID",
  "retrieval_date": "2026-10-24",
  "smiles_stereo_by_ccd": "{\"OCS\": \"C([C@@H](C(=O)O)N)S(=O)(=O)O\"}",
  "source_metadata_sha256": "{\"OCS\": \"be1ee78a9f49ad50013773915d693f4719e23002f8f1d1b196b80b1a91ed9b20\"}",
  "source_urls": [
    "https://www.rcsb.org/ligand/OCS"
  ]
}

Measured target and original context

Bioactivity & experimental observations

Download assay CSV

Each row is one source-specific observation. Repeated measurements of this compound are not independent compounds. Direct binding, functional displacement and cellular outcomes retain their distinct endpoints.

Preparation	Tested target & construct	Method / endpoint	Original observation	Conditions & uncertainty	Source & verification
No observations match these filters. Missing curation is not evidence of biological inactivity.

Exact deposited instances

Experimental structures

Native-core and broader Pfam proximity are distinguished from contacts elsewhere in a protein. Each action opens the actual deposited ligand instance. Geometric proximity does not supply a measured binding affinity.

Entry / ligand	Native domain & protein chain	Geometric evidence	Minimum distance	Inspect
3LYI · OCSPDB:3LYI:LIG:C:OCS:1500:.	BRD1 PWWP1Protein label chain A · ligand label chain C	native annotation core contactunknown chemical componentunknown component · context unresolved. Deposited geometry is not solution affinity.	Core: 3.3409 Å Pfam: 3.3409 Å	View deposited instance

Preparations, identities and controls remain separate

Experimental context

No measured preparation is linked to this deposited identity in the curated snapshot.

Provenance and reproducibility

Sources & downloads

https://www.rcsb.org/ligand/OCS

Download complete evidence JSON Curation methods & source receipts

Snapshot 2026-10-26 · phase5-1.0.0 · original measurements, operators, constructs and uncertainty are retained in the exports.