A saltbridge is defined as a negative atom (side chain
oxygens in Asp or Glu) and a positive atom (side chain
nitrogens in Arg, Lys or His) with an interatomic
distance less than 12.0 Ångstrom. His is considered
positive because it is always easier to tipex the His
results out than to calculate them by hand.
If you have detected any error, or have any question or suggestion,
please send an Email to Gert Vriend.
Roland Krause, Maarten L Hekkelman, Jens E Nielsen,