Exploring QSAR models for activity-cliff prediction

Abstract Introduction and methodology Pairs of similar compounds that only differ by a small structural modification but exhibit a large difference in their binding affinity for a given target are known as activity cliffs (ACs). It has been hypothesised that QSAR models struggle to predict ACs and t...

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Main Authors: Markus Dablander, Thierry Hanser, Renaud Lambiotte, Garrett M. Morris
Format: Article
Language:English
Published: BMC 2023-04-01
Series:Journal of Cheminformatics
Subjects:
Online Access:https://doi.org/10.1186/s13321-023-00708-w
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author Markus Dablander
Thierry Hanser
Renaud Lambiotte
Garrett M. Morris
author_facet Markus Dablander
Thierry Hanser
Renaud Lambiotte
Garrett M. Morris
author_sort Markus Dablander
collection DOAJ
description Abstract Introduction and methodology Pairs of similar compounds that only differ by a small structural modification but exhibit a large difference in their binding affinity for a given target are known as activity cliffs (ACs). It has been hypothesised that QSAR models struggle to predict ACs and that ACs thus form a major source of prediction error. However, the AC-prediction power of modern QSAR methods and its quantitative relationship to general QSAR-prediction performance is still underexplored. We systematically construct nine distinct QSAR models by combining three molecular representation methods (extended-connectivity fingerprints, physicochemical-descriptor vectors and graph isomorphism networks) with three regression techniques (random forests, k-nearest neighbours and multilayer perceptrons); we then use each resulting model to classify pairs of similar compounds as ACs or non-ACs and to predict the activities of individual molecules in three case studies: dopamine receptor D2, factor Xa, and SARS-CoV-2 main protease. Results and conclusions Our results provide strong support for the hypothesis that indeed QSAR models frequently fail to predict ACs. We observe low AC-sensitivity amongst the evaluated models when the activities of both compounds are unknown, but a substantial increase in AC-sensitivity when the actual activity of one of the compounds is given. Graph isomorphism features are found to be competitive with or superior to classical molecular representations for AC-classification and can thus be employed as baseline AC-prediction models or simple compound-optimisation tools. For general QSAR-prediction, however, extended-connectivity fingerprints still consistently deliver the best performance amongs the tested input representations. A potential future pathway to improve QSAR-modelling performance might be the development of techniques to increase AC-sensitivity. Graphical Abstract
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spelling doaj.art-76f3ade697194633a3b30a6242ae36452023-04-23T11:26:37ZengBMCJournal of Cheminformatics1758-29462023-04-0115111610.1186/s13321-023-00708-wExploring QSAR models for activity-cliff predictionMarkus Dablander0Thierry Hanser1Renaud Lambiotte2Garrett M. Morris3Mathematical Institute, University of OxfordLhasa LimitedMathematical Institute, University of OxfordDepartment of Statistics, University of OxfordAbstract Introduction and methodology Pairs of similar compounds that only differ by a small structural modification but exhibit a large difference in their binding affinity for a given target are known as activity cliffs (ACs). It has been hypothesised that QSAR models struggle to predict ACs and that ACs thus form a major source of prediction error. However, the AC-prediction power of modern QSAR methods and its quantitative relationship to general QSAR-prediction performance is still underexplored. We systematically construct nine distinct QSAR models by combining three molecular representation methods (extended-connectivity fingerprints, physicochemical-descriptor vectors and graph isomorphism networks) with three regression techniques (random forests, k-nearest neighbours and multilayer perceptrons); we then use each resulting model to classify pairs of similar compounds as ACs or non-ACs and to predict the activities of individual molecules in three case studies: dopamine receptor D2, factor Xa, and SARS-CoV-2 main protease. Results and conclusions Our results provide strong support for the hypothesis that indeed QSAR models frequently fail to predict ACs. We observe low AC-sensitivity amongst the evaluated models when the activities of both compounds are unknown, but a substantial increase in AC-sensitivity when the actual activity of one of the compounds is given. Graph isomorphism features are found to be competitive with or superior to classical molecular representations for AC-classification and can thus be employed as baseline AC-prediction models or simple compound-optimisation tools. For general QSAR-prediction, however, extended-connectivity fingerprints still consistently deliver the best performance amongs the tested input representations. A potential future pathway to improve QSAR-modelling performance might be the development of techniques to increase AC-sensitivity. Graphical Abstracthttps://doi.org/10.1186/s13321-023-00708-wQSAR modellingActivity cliffsActivity cliff predictionMachine learningDeep learningMolecular representation
spellingShingle Markus Dablander
Thierry Hanser
Renaud Lambiotte
Garrett M. Morris
Exploring QSAR models for activity-cliff prediction
Journal of Cheminformatics
QSAR modelling
Activity cliffs
Activity cliff prediction
Machine learning
Deep learning
Molecular representation
title Exploring QSAR models for activity-cliff prediction
title_full Exploring QSAR models for activity-cliff prediction
title_fullStr Exploring QSAR models for activity-cliff prediction
title_full_unstemmed Exploring QSAR models for activity-cliff prediction
title_short Exploring QSAR models for activity-cliff prediction
title_sort exploring qsar models for activity cliff prediction
topic QSAR modelling
Activity cliffs
Activity cliff prediction
Machine learning
Deep learning
Molecular representation
url https://doi.org/10.1186/s13321-023-00708-w
work_keys_str_mv AT markusdablander exploringqsarmodelsforactivitycliffprediction
AT thierryhanser exploringqsarmodelsforactivitycliffprediction
AT renaudlambiotte exploringqsarmodelsforactivitycliffprediction
AT garrettmmorris exploringqsarmodelsforactivitycliffprediction