In addition, mutants of K147 may also affect the potencies of some antibodies. Research results by McCallum et.al already showed that K147T mutant weakens the potencies of 4A8 (PDB ID: 7C2L), S2X333 (PDB ID: 7LXY) and S2M28 (PDB ID: 7LY2), but has little implication in S2L28 (PDB ID: 7LXZ) , which is in accordance with our prediction about K147 (Figure ).