2019-nCoV vs. SARS-CoV: Which Truly Has a Higher ACE2 Affinity? A Quantum Chemical Perspective on Virus-Receptor Noncovalent Interactions

Noncovalent interaction energetics associated with ACE2 affinity differences are investigated using electronic structure methods; Our results were found to challenge previous predictions – claiming a higher affinity for 2019-nCoV compared to SARS-CoV based merely on "chemical intuition". In addition, we demonstrate that a broadly-used classical molecular dynamics force field – MMFF94 – is clearly incapable of reproducing DFT-based noncovalent interaction energetics for the systems at hand (despite being specifically parameterized for van der Waals interactions).