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Target Snapshot

CHEMBL4338 Target Snapshot

Purine nucleoside phosphorylase · SINGLE PROTEIN · Homo sapiens

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439Compounds
156Assays
6Approved Drugs
625.0Activities
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Broader Open DB context

Frame the target before identity details

Structured disease, protein, and project context should read before the lower-level identity rail.

As of 2026-09-14

Purine nucleoside phosphorylase shows clinical signal disease relevance led by chronic lymphocytic leukemia. 5 more disease programs remain visible in the same review block. 1 linked drug keeps the current disease frame grounded. Protein identity stays anchored to UniProt P00491. Start with chronic lymphocytic leukemia, then reuse UniProt P00491 as the stable protein anchor across project notes and exports.

Review focus
Review-ready target frame

Start with chronic lymphocytic leukemia, then reuse UniProt P00491 as the stable protein anchor across project notes and exports.

ChEMBL component mapping + Open Targets-ready proxy + ChEMBL 36 via Core Engine 2026-09-14 1 linked drug
Open source guide
Disease program
chronic lymphocytic leukemia

Purine nucleoside phosphorylase shows clinical signal disease relevance led by chronic lymphocytic leukemia. 5 more disease programs remain visible in the same review block. 1 linked drug remains visible in the same block.

Start review with chronic lymphocytic leukemia because it currently carries clinical signal support. Linked drugs include FORODESINE HYDROCHLORIDE. This disease block keeps the Open Targets-ready contract explicit while current evidence comes from ChEMBL mechanism and indication mappings.

Disease source · ChEMBL drug mechanism + indication proxy
Clinical signal Open Targets-ready proxy 1 linked drug
Open disease block
Identity Layer

Cross-source identity

Keep the review anchor, source IDs, and context contract aligned before reusing this target elsewhere.

This review treats Purine nucleoside phosphorylase as ChEMBL target CHEMBL4338, mapped to UniProt P00491. Disease framing currently uses the Open Targets-ready proxy contract.

Review anchor
Purine nucleoside phosphorylase
SINGLE PROTEIN · Homo sapiens
As of 2026-09-14
ChEMBL target ID
CHEMBL4338
Primary anchor for compounds, assays, approvals, and exports
ChEMBL 36 via Core Engine As of 2026-09-14
www.ebi.ac.uk
UniProt accession
P00491
Purine nucleoside phosphorylase
UniProt accession via ChEMBL component mapping As of 2026-09-14
www.uniprot.org
Disease evidence contract
Open Targets-ready proxy
ChEMBL drug mechanism + indication proxy
ChEMBL drug mechanism + indication proxy As of 2026-09-14
www.ebi.ac.uk

Reuse the same identifiers in notes, watch rules, exports, and review packs so provenance stays stable across surfaces.

Source Guidance

Start with the right source

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Need stable target naming and protein identity?
UniProt Target Context
UniProt accession via ChEMBL component mapping

Start here when your first question is whether Purine nucleoside phosphorylase is the right protein anchor across sources, using UniProt P00491 as the stable mapping.

Jump to Protein Context
Need disease fit before discussing compounds?
Disease Relevance & Evidence Level
ChEMBL drug mechanism + indication proxy

Use this block first when you need to confirm why chronic lymphocytic leukemia is currently framed as clinical signal support. It currently carries 1 linked drug in the same disease frame.

Jump to Disease Context
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Evidence Card
Review-ready rationale with source-aware context

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Overview

Basic Information

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Preferred NamePurine nucleoside phosphorylase
Target TypeSINGLE PROTEIN
OrganismHomo sapiens
UniProtP00491
ChEMBL ↗ UniProt ↗ NCBI Protein ↗

Next Actions

SearchRun a focused querySearch the database using this target name as the starting context. ApprovalsCheck approved moleculesSee which approved drugs connect back to this target and its surrounding signal space. FeedScan papers & updatesStay in the project thread while checking recent papers and platform updates.
UniProt Context

UniProt Target Context

Reviewable protein naming and mapping context for this target snapshot.

Protein LabelPurine nucleoside phosphorylase
UniProt AccessionP00491
Component TypeProtein
Sequence Length289 aa

Purine nucleoside phosphorylase

Source · UniProt accession via ChEMBL component mapping
UniProt Context ↗
Review Cue

How to read this target

Review this target as Purine nucleoside phosphorylase, mapped to UniProt P00491. Sequence length is 289 aa.

Mapped IDP00491
Review namePurine nucleoside phosphorylase
OrganismHomo sapiens
Disease Relevance

Disease Relevance & Evidence Level

Open Targets-ready disease context using the current target-indication evidence contract.

Clinical signal Open Targets-ready proxy

Purine nucleoside phosphorylase shows clinical signal disease relevance led by chronic lymphocytic leukemia. 5 more disease programs remain visible in the same review block.

Clinical signal Phase II
chronic lymphocytic leukemia
1 linked drug · 1 direct · 1 efficacy
Linked drugFORODESINE HYDROCHLORIDE
Clinical signal Phase II
gout
1 linked drug · 1 direct · 1 efficacy
Linked drugULODESINE
Clinical signal Phase II
hyperuricemia
1 linked drug · 1 direct · 1 efficacy
Linked drugULODESINE
Clinical signal Phase II
osteoarthritis
1 linked drug · 1 direct · 1 efficacy
Linked drugULODESINE
Clinical signal Phase I
cancer
1 linked drug · 1 direct · 1 efficacy
Linked drugFORODESINE HYDROCHLORIDE
Clinical signal Phase I
lymphoid leukemia
1 linked drug · 1 direct · 1 efficacy
Linked drugFORODESINE HYDROCHLORIDE
Source · ChEMBL drug mechanism + indication proxy
ChEMBL target record ↗
Review Cue

How to read disease relevance

Start review with chronic lymphocytic leukemia because it currently carries clinical signal support. Linked drugs include FORODESINE HYDROCHLORIDE. This disease block keeps the Open Targets-ready contract explicit while current evidence comes from ChEMBL mechanism and indication mappings.

Lead diseasechronic lymphocytic leukemia
Strongest levelClinical signal
Block modeOpen Targets-ready proxy
Clinical Profile

Clinical Phase Distribution

6
Approved
2
Phase III
5
Phase II
Assay Mix

Activity Type Distribution

IC50220.0
KI369.0
KD36.0
Lead Set

Top Inhibitors (by pChEMBL)

ChEMBL IDpChEMBLTypeValue (nM)Phase
CHEMBL269864 10.97 Ki 0.0107 Clinical
CHEMBL514795 10.71 Ki 0.0196 Preclinical
CHEMBL473922 10.54 Ki 0.029 Preclinical
CHEMBL349855 10.52 IC50 0.03 Preclinical
CHEMBL498940 10.49 Ki 0.032 Preclinical
CHEMBL218291 10.25 Kd 0.056 Approved
CHEMBL218291 10.25 Ki 0.056 Approved
CHEMBL1213652 10.24 Kd 0.058 Preclinical
CHEMBL349024 10.24 IC50 0.057 Preclinical
CHEMBL218291 10.22 IC50 0.06 Approved
Distribution

pChEMBL Value Distribution

24
5.0
33
5.5
42
6.0
64
6.5
78
7.0
71
7.5
67
8.0
34
8.5
29
9.0
19
9.5
pChEMBL
Approved Drugs

Approved Drugs

FORODESINE
CHEMBL218291
Approved 2017
Properties Compare Identifier
FORODESINE HYDROCHLORIDE
CHEMBL550755
Approved 2017
Properties Compare Identifier
CLADRIBINE
CHEMBL1619
Approved 1993
Properties Compare Identifier
ACYCLOVIR
CHEMBL184
Approved 1982
Properties Compare Identifier
Assay Landscape

Assay Landscape

156
Total Assays
378
Tested Compounds
3
Assay Types
Binding — 139 assays, 378 compounds
BAO Format Assays Compounds Avg pChEMBL
single protein format 96 227 7.6
assay format 15 82 6.9
cell-based format 14 10 7.7
tissue-based format 14 59 7.4
Functional — 16 assays, 8 compounds
BAO Format Assays Compounds Avg pChEMBL
assay format 16 8 6.6
ADME — 1 assays, 0 compounds
BAO Format Assays Compounds Avg pChEMBL
single protein format 1 0 —

Confidence Score Distribution

Source · ChEMBL 36 via Core Engine