Figure 5: Possible H-bonds between NOVs and the GLU235 residue. (A) Two H-bonds are formed on NOV(P) at pH 7, whereas only one H-bond is formed on NOV(P) at pH 5X (B) and on NOV(S) at pH 7 (C). (D) NOV(S) at pH 5X can provide two H-bonds.