## Endpoint to Predict
- Endpoint scope: assay
- Measurement type: Ki
- Label type: continuous
- Binary semantics: pchembl
- Assay description: Monoamine Oxidase Assays for Determining the Selectivity of the Compounds of the Invention for LSD1: Human recombinant monoamine oxidase proteins MAO-A and MAO-B were purchased from Sigma Aldrich. MAOs catalyze the oxidative deamination of primary, secondary and tertiary amines. In order to monitor MAO enzymatic activities and/or their inhibition rate by inhibitor(s) of interest, a fluorescent-based (inhibitor)-screening assay was set up. 3-(2-Aminophenyl)-3-oxopropanamine (kynuramine dihydrobromide, Sigma Aldrich), a non fluorescent compound was chosen as a substrate. Kynuramine is a non-specific substrate for both MAOs activities. While undergoing oxidative deamination by MAO activities, kynuramine is converted into 4-hydroxyquinoline (4-HQ), a resulting fluorescent product.The monoamine oxidase activity was estimated by measuring the conversion of kynuramine into 4-hydroxyquinoline. Assays were conducted in 96-well black plates with clear bottom (Corning) in a final volume of 100 μL. The assay buffer was 100 mM HEPES, pH 7.5. Each experiment was performed in triplicate within the same experiment.Briefly, a fixed amount of MAO (0.25 μg for MAO-A and 0.5 μg for MAO-B) was incubated on ice for 15 minutes in the reaction buffer, in the absence and/or in the presence of various concentrations of inhibitor (e.g., from 0 to 50 μM, depending on the inhibitor strength). Tranylcypromine (Biomol International) was used as a control for inhibition.After leaving the enzyme(s) interacting with the inhibitor, 60 to 90 μM of kynuramine was added to each reaction for MAO-B and MAO-A assay respectively, and the reaction was left for 1 hour at 37° C. in the dark. The oxidative deamination of the substrate was stopped by adding 50 μL (v/v) of NaOH 2N. The conversion of kynuramine to 4-hydroxyquinoline, was monitored by fluorescence (excitation at 320 nm, emission at 360 nm) using a microplate reader (Infinite 200, Tecan). Arbitrary units were used to measure levels of fluorescence produced in the absence and/or in the presence of inhibitor.The maximum of oxidative deamination activity was obtained by measuring the amount of 4-hydroxyquinoline formed from kynuramine deamination in the absence of inhibitor and corrected for background fluorescence in the absence of MAO enzymes.
- Assay organism: Homo sapiens
- Target name: Amine oxidase [flavin-containing] B
- Target type: SINGLE PROTEIN
- Target organism: Homo sapiens

## Reference Molecule A
- Canonical SMILES: Nc1nnc(CN[C@H]2C[C@@H]2c2ccc(OCc3ccccc3)cc2)o1
- Properties:
- ChEMBL ID: CHEMBL6014057
- Molecular weight: 336.4
- Heavy atoms: 25
- Hydrogen bond donors: 2
- Hydrogen bond acceptors: 6
- TPSA: 86.2
- LogP: 2.88
- Rotatable bonds: 7
- Ring count: 4
- Aromatic rings: 3
- Formal charge: 0
- Fraction Csp3: 0.26
- QED: 0.69

## Known Reference Result on This Endpoint
- Molecule A clean result: median pChEMBL = 6.26
- This result is provided as context for predicting Molecule B on the same endpoint.

## Reference Molecule A Other ChEMBL Evidence
- type Ki; relation =; value 550; units nM; pChEMBL 6.26; comment 731420

## Query Molecule B
- Canonical SMILES: Nc1ncc(CN[C@H]2C[C@@H]2c2ccc(OCc3ccccc3)cc2)cn1
- Properties:
- ChEMBL ID: CHEMBL5915787
- Molecular weight: 346.43
- Heavy atoms: 26
- Hydrogen bond donors: 2
- Hydrogen bond acceptors: 5
- TPSA: 73.06
- LogP: 3.28
- Rotatable bonds: 7
- Ring count: 4
- Aromatic rings: 3
- Formal charge: 0
- Fraction Csp3: 0.24
- QED: 0.69

## Molecule Similarity
- Weighted Tanimoto: 0.66

Answer: 6.26