Entospletinib

Protein target name:

SYK

Mechanism of action:

Inhibitor

Recommended Concentration for use in cells:

~~up to 10 uM~~

Reviewer suggested Concentration for use in cells:

up to 1 uM

Probe Availability

MedChemExpress

Selleck Chemicals

Probe Information

Target and Probe Information

Target Details

Target class:

Protein kinase

Subclass:

HUGO ID:

HGNC:11491

Entrez gene ID:

6850

UNIPROT ID:

P43405

Target alias:

Spleen associated tyrosine kinase, p72-Syk

Probe Details

Chemical Probes Portal ID:

CPP1209

Probe alias:

GS-9973, cpd 68, CG9

PubChem CID:

59473233

ChEMBL ID:

CHEMBL3265032

SMILES string:

C12=NC=CN1C=C(C3=CC4=C(C=C3)C=NN4)N=C2NC5=CC=C(N6CCOCC6)C=C5

InChi Key:

XSMSNFMDVXXHGJ-UHFFFAOYSA-N

Orthogonal probe:

PRT062607

Physico-chemical properties

NMR:

1H NMR (300 MHz, DMSO-d6) δ 13.17 (s, 1H), 9.50 (s, 1H), 8.66 (s, 1H), 8.19 (s, 1H), 8.09 (s, 1H), 8.03 (d, J = 8.7 Hz, 2H), 7.99 (d, J = 0.9 Hz, 1H), 7.84 (d, J = 8.7 Hz, 1H), 7.72 (dd, J = 8.7, 0.9 Hz, 1H), 7.63 (d, J = 0.9 Hz, 1H), 7.00 (d, J = 8.7 Hz, 2H), 3.77 (t, J = 4.6 Hz, 4H), 3.11 (t, J = 4.6 Hz, 4H)

Validation in Cells and Model Organisms

In vitro validation

On target activity

Potency:

IC50

7.7 nM

Potency assay:

SYK enzymatic assay (Lance-based assay)

PDB ID for probe-target interaction (3D structure):

4PUZ

Structure-activity relationship:

yes

Off target activity

Probe Selectivity in Vitro:

Profiled using the KinomeScan platform against a panel of 359 nonmutant kinases at a single concentration of 10 μM. Kd values were determined for 67 kinases and only TNK1 showed less than 10-fold selectivity versus Syk.

In cell validation

On target activity in cells

Potency in cells:

EC50

26 nM

Potency assay (cells):

MSD assay detecting the substrate pBLNK

Off target activity in cells

Potency assay, off target (cells):

target protein phosphorylation assay

Probe Selectivity in Cell:

In cells, Entospletinib inhibited Flt3, Jak2, c-Kit, KDR, and Ret with 13- to >1000-fold cellular selectivity for Syk as assessed by target protein phosphorylation or functional response.

In vivo validation

Organism:

Rat, Dog

Dose:

0.4 (IV), 1 (PO) mg/Kg

Route of delivery:

OralIntravenous

Plasma half life:

35 (R), 23.4 (D) min

Systemic clearance:

0.27 (R), 0.80 (D) L/h/kg

Fraction of probe bound to plasma protein:

99.2 (R), 92.8 (D) %

Primary Reference

Reference (doi):

10.1021/jm500228a

Reference (PMID):

24779514

Endorsed probe

The Chemical Probes Portal endorses this compound as chemical probe for use in cells and in model organisms.

SAB Rating

Rating for use in Cells

3 review(s)

Rating for use in Model Organisms

3 review(s)

SAB Members

SAB Comments

Although quite selective, it is important to note that cellular effects of Jak2, ckit, and Flt3 inhibition are seen at EC50 values of 330-450 nM. If these kinases may be relevant to the pathway of interest, it will be important to stick to lower concentrations of the probe to avoid confusion. I would not recommend going above 1 uM in cells given the activity against other kinases. Regarding in vivo use in rats, although reduction of ankle inflammation was observed when dosed orally at 1 mg /kg bid, other anti-inflammatory effects were less prominent until dosing at 3 mg/kg, and the molecule was tested up to 10 mg/kg in rats.

Aug 4 2021 - 10:06pm

Entospletinib required formulation in NMP/PEG-400 to determine its PK in CD1 mice due to its poor solubility. This solubility needs to be improved to improve its utility in vivo.

Aug 26 2021 - 9:50am

Reviewer recommended dose in vivo: use both 1 mg/mL and 3 mg/mL dosing regimen for in vivo studies as higher dose resulted in at least 50% target coverage (pSyk EC50).

Sep 13 2021 - 3:05pm

Entospletinib

Probe Availability

Probe Information

Target Details

Spleen associated tyrosine kinase, p72-Syk

Probe Details

Physico-chemical properties

In vitro validation

In cell validation

In vivo validation

Primary Reference

Supporting Organizations

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Entospletinib

Probe Availability

Probe Information

Target Details

Spleen associated tyrosine kinase, p72-Syk

Probe Details

Physico-chemical properties

In vitro validation

In cell validation

In vivo validation

Primary Reference

Supporting Organizations

Interested in supporting the portal?