The results of binding free energy (ΔG) with glycans' contribution are hard to reproduce in each experiment (Table ). In order to exploring more details, 500ns MD simulation was executed for 7L2F complex. As indicated in Figure , the three flexible sugars (N17, N74, N122 glycan), especially N17 glycan, move intensely and stay closed to the antibody within 3 angstroms most of the time for wild type complex (Figure ), while for R246I complex, the sugars are more than 5 angstroms away from the antibody in most of the time (Figure ). What's more, the energy contribution of glycans varies between -2.75 and -26.82 kcal/mol in the wild type complex, but only between -9.02 and 2.76 kcal/mol in the R246I mutant (Figure ).