AID	Name	Type	Comment
1707	Counterscreen for APE1 Inhibitors: Fluorescent Dye Displacement Validation Assay	confirmatory	Primary qHTS assay for APE1 inhibitors
1708	Counterscreen for APE1 Inhibitors: qHTS Validation Assay for Inhibitors of Endonuclease IV	confirmatory	EndoIV counterscreen
1705	qHTS Validation Assay for Inhibitors of the Human Apurinic/apyrimidinic Endonuclease 1 (APE1)	confirmatory	DNA binding counterscreen
2573	qHTS FP-Based Assay for Inhibitors of the Human Apurinic/apyrimidinic Endonuclease 1 (APE1)	confirmatory	FP counterscreen
2324	Probe Development Summary of Inhibitors of the Human Apurinic/apyrimidinic Endonuclease 1 (APE1)	summary

The apurinic/apyrimidinic endonuclease APE1 is the primary mammalian enzyme responsible for the removal of abasic (or AP) sites in DNA and functions centrally in the base excision DNA repair (BER) pathway. Recent studies suggested a link between an overexpression of APE1 in many cancers and resistance of these tumor cells to radio- and chemotherapy. Thus, targeting APE1 could improve the efficacy of current treatment paradigms by promoting selective sensitization or protection of diseased and normal cells, respectively.

This bioassay provides profiling data on aqueous kinetic solubility (PBS @ pH 7.4) of one of the lead compounds developed in the APE1 inhibitors project.

APE1 Project Principal Investigator: David M. Wilson, III, National Institute on Aging, NIH
Screening Center PI: Austin, C.P.
Screening Center: NIH Chemical Genomics Center [NCGC]

1. 8ul of reference and test compound stock solution were added to 392ul 100mM phosphate buffer (pH 7.4)

2. Sample tubes were shaken for 1 hr (1000 rpm) at room temperature

3. Samples were centrifuged (10 min at 12000 rpm) to precipitate un-dissolved particles

4. Supernatants were transferred to new tubes

5. Concentration of the supernatant was determined by LC-UV or LC-MS/MS

Compounds are "active" if solubility is greater than 20; "inconclusive" if solubility is between 10 and 20; "inactive" if solubility is less than 10.

PUBCHEM_ACTIVITY_SCORE is the solubility rounded to the closet whole number.

Grant Number: MH086444-01