## Endpoint to Predict
- Endpoint scope: assay
- Measurement type: IC50
- Label type: continuous
- Binary semantics: pchembl
- Assay description: Measurement of Brk Inhibitory Activity: Measurement of an inhibitory activity on Brk enzyme was performed by using LanthaScreen (registered trademark) system (Invitrogen) in accordance with the attached manual. Reagents used are described below.Reaction Buffer: A solution containing 50 mmol/L HEPES (pH 7.5), 0.01% Brij 35, 10 mmol/L MgCl2 and 1 mmol/L EGTA was prepared by using purified water.A solution of a test substance (the compound of the present invention): A solution of each concentration of a test compound in DMSO was diluted 20-fold with Reaction Buffer, and a solution containing a test compound at a concentration 5 times a final concentration was prepared.An enzyme solution: A solution containing 480 ng/mL of Brk enzyme was prepared by using Reaction Buffer.A substrate solution: A solution containing 57 μmol/L of ATP and 500 nmol/L of Fluorescein-Poly GT (Invitrogen) was prepared by using Reaction Buffer.A detection solution: A solution containing 20 mmol/L of EDTA and 4 nmol/L of PY20 (Invitrogen) was prepared by using Dilution B (Invitrogen).To a 96-well plate (Nunc), a solution of 10 mmol/L of a test compound in DMSO was dispensed, and further, a dilution series at a common ratio of three was prepared by using DMSO. To each of wells of the 96-well plate for the measurement, 5 μL of Reaction Buffer containing DMSO was added for a blank group and a vehicle group and 5 μL of a test substance solution was added for a test substance group. Next, 10 μL per well of Reaction Buffer was added for the blank group, and 10 μL per well of the enzyme solution was added for the vehicle group and the test compound group, and thereafter, the mixture was stirred at room temperature for 10 minutes. After completion of stirring, 10 μL of the substrate solution was added to each of wells, and the mixture was stirred at room temperature under a shading condition for 1 hour. After completion of the reaction, 25 μL of the detection solution was added to each well, and the mixture was left to stand at room temperature under a shading condition for 30 minutes. After being left standing, fluorescence intensities at 520 nm and 495 nm were measured by using Analyst GT (Molecular Devices, LLC) when being irradiated with an excitation light at 340 nm. The phosphorylation of the artificial substrate was quantified by Time-Resolved Fluorescence Resonance Energy Transfer (TR-FRET). With regard to each well, the TR-FRET ratio was calculated by divining the fluorescence signal at 520 run by the fluorescence signal at 495 nm, and the inhibition rate (%) in the test compound group was calculated according to the following Numerical Formula 1.Inhibition rate (%)={1−(TR-FRET ratio of test compound group−A)/(B−A)}×100 [Numerical Formula 1].
- Assay organism: Homo sapiens
- Target name: Protein-tyrosine kinase 6
- Target type: SINGLE PROTEIN
- Target organism: Homo sapiens

## Reference Molecule A
- Canonical SMILES: CS(=O)(=O)c1ccc(Nc2nc(N)c3c(n2)n(C2CCCC2)c(=O)n3-c2cccc3[nH]ncc23)c(F)c1
- Properties:
- ChEMBL ID: CHEMBL5874804
- Molecular weight: 522.57
- Heavy atoms: 37
- Hydrogen bond donors: 3
- Hydrogen bond acceptors: 8
- TPSA: 153.58
- LogP: 3.44
- Rotatable bonds: 5
- Ring count: 6
- Aromatic rings: 5
- Formal charge: 0
- Fraction Csp3: 0.25
- QED: 0.32

## Known Reference Result on This Endpoint
- Molecule A clean result: median pChEMBL = 8.7
- This result is provided as context for predicting Molecule B on the same endpoint.

## Reference Molecule A Other ChEMBL Evidence
- type IC50; relation =; value 2; units nM; pChEMBL 8.7; comment 1077906

## Query Molecule B
- Canonical SMILES: CS(=O)(=O)c1ccc(Nc2nc(N)c3c(n2)n(C2CCC2)c(=O)n3-c2cccc3[nH]ncc23)c(F)c1
- Properties:
- ChEMBL ID: CHEMBL5843422
- Molecular weight: 508.54
- Heavy atoms: 36
- Hydrogen bond donors: 3
- Hydrogen bond acceptors: 8
- TPSA: 153.58
- LogP: 3.05
- Rotatable bonds: 5
- Ring count: 6
- Aromatic rings: 5
- Formal charge: 0
- Fraction Csp3: 0.22
- QED: 0.33

## Molecule Similarity
- Weighted Tanimoto: 0.98

Answer: 8.3