Before revision:  To better understand the relationship between the virus and its human host, we used a structure-based computational model to interrogate the effects of mutations in the interfacebetween the MACV spike glycoprotein ( MACVGP) and the Human transferrin receptor (hTfR1) . Existing computational methods to probe protein-protein interactions perform poorly with non-alanine mutations and on the flexible loops encountered in many host-virus interactions. We applied steered molecular dynamics (SMD) simulations to induce protein dissociation; using descriptive statistics, we were able to differentiate mutant complexes and biochemically rationalize available infectivity data. The previously published co-crystal structure implies two important hydrogen bonding networks in the MACVGP /hTfR1 interface ;
After revision:  To better understand the relationship between the virus and its human host, we used a structure-based computational model to interrogate the effects of mutations in the interfacebetween the MACV spike glycoprotein ( MACVGP) and the Human transferrin receptor (hTfR1) and estimate affinity using the maximum applied force during a pulling simulation and the area under the force-versus-distance curve. We find that these quantities provide novel biophysical insight into the GP1/hTfR1 interaction. First, with no prior knowledge of the system we can differentiate among wild-type and mutant complexes. Second, although the static co-crystal structure implies two important hydrogen bonding networks in the MACVGP /hTfR1 interface ;