Fast assessment of human receptor-binding capability of 2019 novel coronavirus (2019-nCoV)

Qiang Huang; Andreas Herrmann

The successful identification of the experimental complex structure as the lowest-energy binding conformations also validates the accuracy of the used Rosetta all-atom energy function (Alford et al., 2017) for quantifying the interactions of S-RBD with ACE2. As we will show, we could use the thermodynamic average of the binding energy scores of these conformations as an experiment-based energy reference to characterize the interactions of the 2019-nCoV S-RBD binding to ACE2, and then to evaluate the relative strength with respect to that of SARS-CoV. Such a comparison assessment avoids using the calculated, absolute free-energy scores to correlate with the binding strength, which might systematically differ from the actual measurement values because of the intrinsic, theoretical approximations of the used Rosetta all-atom energy function (Alford et al., 2017) . We want to point out that all the docking simulations for SARS-CoV and 2019-nCoV use the same protocols and a consistent all-atom energy function. So, even the calculated energy scores contain certain errors caused by theoretical approximations, determination of the relative binding strength by comparing the calculated energy scores of two viruses should be fairly accurate.