Fig. 4

Free cysteine residues 54C, 61C and 192C in the S–S open model disorient residues involved in trans-GJ interactions. A Number of trans-GJ H-bonds (left) and specific residue pairs forming these trans-GJ H-bonds (right) during the 100 ns MD in the HC-HC model with closed disulfides. Colour bar shows the number of subunit pairs on which the specific trans-GJ H-bonds is present. B Number of trans-GJ H-bonds (left) and specific residue pairs forming these trans-GJ H-bonds (right) during the 100 ns MD in the HC-HC model with HCs positioned 3 Å away. Colour bar shows the number of subunit pairs on which the specific trans-GJ H-bonds is present. C Number of trans-GJ H-bonds (left) and specific residue pairs forming these trans-GJ H-bonds (right) during the 100 ns MD in the HC-HC model with open disulfides. Colour bar shows the number of subunit pairs on which the specific trans-GJ H-bonds is present. D Number of H-bonds involving Cys residues (left) and specific residue pairs forming these H-bonds (right) during the 100 ns MD in the HC-HC model with open Cys disulfides. Colour bar shows the number of subunit pairs on which the specific Cys-interface H-bond is present. E 3D representation of the HC-HC interface shows disorientation of 58Q from the position required to make trans-GJ H-bonding. Trans-GJ H-bonds between opposing 58Q residues are formed in the HC-HC model with closed disulfides (top). In the open disulfide model (bottom) 58Q oxygen atoms are involved in H-bonds with Cys thiol residues instead of forming trans-GJ interactions