Binder profile

HPA

Ligand co-crystallized with a similar protein (Protein Data Bank).

Bound to: PA1523 — xanthine dehydrogenase

Via homolog PDB 3nrz UniProt P80457 C5H4N4O
Mol. weight 136.11 Da
Permeability High
PAINS Clean

Identifiers

Database identifiers and provenance.

Ligand ID
HPA
PDB
3nrz
UniProt (similar protein)
P80457
Target protein
PA1523

Structure

2D representation rendered from SMILES.

Physicochemical properties

Computed with RDKit from SMILES.

Molecular weight 136.11 Da
LogP (Crippen) -0.35
H-bond donors 2
H-bond acceptors 3
TPSA 74.43 Ų
Rotatable bonds 0
Aromatic rings 2 / 2
Heavy atoms 10
Fraction sp³ C 0.00
Formula C5H4N4O

Drug-likeness

Descriptor-based ADME screening flags from SMILES. These are not experimental toxicity results.

Permeability proxy High

Estimated from TPSA and LogP only: TPSA ≤ 90 Ų and −1 ≤ LogP ≤ 5 are treated as a favorable small-molecule permeability screen.

Lipinski's Rule of Five Pass 0 violations
  • MW ≤ 500 Da 136.1
  • LogP ≤ 5 -0.35
  • H-bond donors ≤ 5 2
  • H-bond acceptors ≤ 10 3
Veber's rules Pass
  • Rotatable bonds ≤ 10 0
  • TPSA ≤ 140 Ų 74.4
PAINS Clean

No PAINS structural alerts detected.

Chemical representations

Canonical representations for cheminformatics workflows.

SMILES 
c1[nH]c2c(n1)N=CNC2=O
InChI 
InChI=1S/C5H4N4O/c10-5-3-4(7-1-6-3)8-2-9-5/h1-2H,(H2,6,7,8,9,10)
InChIKey 
FDGQSTZJBFJUBT-UHFFFAOYSA-N

Provenance

Annotation context from LigQ_2, the internal TPW step that collects PDB, ChEMBL, and ZINC ligand evidence.

Method
LigQ nearest_k
Source
PDB
Binding sites
PF02738' 'PF20256

External resources

Open this ligand in third-party databases and cheminformatics tools.

Other binders for this protein

Quick navigation to other ligands bound to PA1523.

PDB 19

Ligands co-crystallized with this protein (structural evidence).

Ligand PDB entry

ChEMBL 100

Compounds with measured inhibitory activity on this target (higher pchembl = more potent).

Compound Potency (pchembl)

ZINC 50

Virtual screening candidates selected by structural similarity to known actives (Tanimoto ≥ 0.5).

Compound Similarity (Tanimoto)