Screening of Therapeutic Agents for COVID-19 using Machine Learning and Ensemble Docking Simulations

The world has witnessed unprecedented human and economic loss from the COVID-19 disease, caused by the novel coronavirus SARS-CoV-2. Extensive research is being conducted across the globe to identify therapeutic agents against the SARS-CoV-2. Here, we use a powerful and efficient computational strategy by combining machine learning (ML) based models and high-fidelity ensemble docking simulations to enable rapid screening of possible therapeutic molecules (or ligands). Our screening is based on the binding affinity to either the isolated SARS-CoV-2 S-protein at its host receptor region or to the Sprotein-human ACE2 interface complex, thereby potentially limiting and/or disrupting the host-virus interactions. We first apply our screening strategy to two drug datasets (CureFFI and DrugCentral) to identify hundreds of ligands that bind strongly to the aforementioned two systems. Candidate ligands were then validated by all atom docking simulations. The validated ML models were subsequently used to screen a large bio-molecule dataset (with nearly a million entries) to provide a rank-ordered list of ~19,000 potentially useful compounds for further validation. Overall, this work not only expands our knowledge of small-molecule treatment against COVID-19, but also provides an efficient pathway to perform high-throughput computational drug screening by combining quick ML surrogate models with expensive high-fidelity simulations, for accelerating the therapeutic cure of diseases.