Beginner Puzzle:Streptococcal Protein 2ZW1 Optimizing pH-response of affinity between Protein G and IgG Fc: How electrostatic modulations affect protein-protein interactions Watanabe, H., Matsumaru, H., Ooishi, A., Feng, Y., Odahara, T., Suto, K., Honda, S. Journal: (2009) J.Biol.Chem.