KSQ 4279

Name: KSQ 4279
Brand: Tocris Bioscience
SKU: 7746

Tocris Bioscience, part of Bio-Techne | Catalog # 7746

COA / SDS

Potent and selective USP1 allosteric inhibitor

Key Product Details

Description:	Potent and selective USP1 allosteric inhibitor
Alternative Names:	Ubiquitin-specific Protease 1 Inhibitor 1,USP1-IN-1,USP1 Inhibitor 1,RO7623066
Chemical Name:	6-(4-Cyclopropyl-6-methoxypyrimidin-5-yl)-1-(4-(1-isopropyl-4-(trifluoromethyl)-1H-imidazol-2-yl)benzyl)-1H-pyrazolo[3,4-d]pyrimidine
Purity:	≥98% (HPLC)
Molecular Weight:	534.54

View Full Technical Details for KSQ 4279

Technical Data
Citations

Biological Activity for KSQ 4279

KSQ 4279 is a potent and selective allosteric inhibitor of the ubiquitin specific protease 1 (USP1) (IC₅₀ = 11 nM; Ki = 1.2 nM), a key regulator of DNA damage repair pathway (distinct from PARP inhibitors). It displays selectivity for USP1 over other USP, UCH and OTU enzymes.

KSQ 4279 has strong antiproliferation effects in vitro. It induces accumulation of mono-ubiquitinated substrates in MDA-MB-436 cells.

In vivo, KSQ 4279 induces anti-tumor response in the BRCA1 mutant ovarian PDX model (mouse). It also displays synergistic effects with PARP inhibitor Olaparib (Cat. No. 7579) leading to significant and durable anti-tumor response in mice. KSQ 4279 is orally bioavailable.

Technical Data for KSQ 4279

M. Wt	534.54
Formula	C₂₇H₂₅F₃N₈O
Storage	Store at -20°C
Purity	≥98% (HPLC)
CAS Number	2446480-97-1
PubChem ID	150782011
InChi Key	KCBWAFJCKVKYHO-UHFFFAOYSA-N
Smiles	FC(F)(C1=CN(C(C)C)C(C2=CC=C(CN3N=CC4=C3N=C(C5=C(C6CC6)N=CN=C5OC)N=C4)C=C2)=N1)F

The technical data provided above is for guidance only. For batch specific data refer to the Certificate of Analysis.

Tocris products are intended for laboratory research use only, unless stated otherwise.

Solubility for KSQ 4279

	Solvent	Max Conc. mg/mL	Max Conc. mM
Solubility
	DMSO	53.45	100
	ethanol	53.45	100

Preparing Stock Solutions for KSQ 4279

The following data is based on the product molecular weight 534.54.

Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which will affect the solvent volumes required to prepare stock solutions.

Concentration / Solvent Volume / Mass	1 mg	5 mg	10 mg
1 mM	1.87 mL	9.35 mL	18.71 mL
5 mM	0.37 mL	1.87 mL	3.74 mL
10 mM	0.19 mL	0.94 mL	1.87 mL
50 mM	0.04 mL	0.19 mL	0.37 mL

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References for KSQ 4279

References are publications that support the biological activity of the product.

Li Design, synthesis, and biological evaluation of pyrido[2,3-d]pyrimidin-7(8H)-one derivatives as potent USP1 inhibitors. Eur.J.Med.Chem. 2024 PMID: 38889606
Cadzow The USP1 inhibitor KSQ-4279 overcomes PARP inhibitor resistance in homologous recombination-deficient tumors. Cancer Res. 2024 PMID: 39402989
Nusawardhana USP1-dependent nucleolytic expansion of PRIMPOL-generated nascent DNA strand discontinuities during replication stress. Nucleic Acids Research 2024 PMID: 38180818