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

Qiang Huang; Andreas Herrmann

Here, we employ protein-protein docking approach to quantify the interactions of 2019-nCoV S-RBD with ACE2, based on the experimentally determined structure of SARS-CoV S-RBD complexed with ACE2 (Li et al., 2005) and on the predicted structure of 2019-nCoV S-RBD according to gene sequence. Computational protein-protein docking with accurate, physics-based energy functions is able to reveal the native-like, low-energy protein-protein complex from the unbound structures of two individual, interacting protein components (Chaudhury et al., 2011) , such as antibody-antigen structures (Weitzner et al., 2017) , and thereby may calculate the binding free energy of the investigated protein-protein interactions. To this end, large-scale local protein-protein docking was first carried out to sample a large number of thermodynamically probable conformations for the S-RBD binding to ACE2. Next, the binding free energy of S-RBD to ACE2 was calculated according to the thermodynamic average over the sampled, low-energy binding conformations. Our results show that the human receptor-binding affinity of 2019-nCoV is about 73% of that of SARS-CoV, implying that 2019-nCoV is able to bind to ACE2, and thereby infects the human host cells like SARS-CoV.