Jacqueline Berges1, Franck Fuster1, Bernard Silvi1, Jean-Pierre Jacquot2, Chantal Houee-Levin3
1 Laboratoire de Chimie Theorique UMR 7616, Universite Paris VI, 4, place Jussieu 75005 Paris, France,
2 Laboratoire de Biologie Forestiere Associe INRA, Universite de Nancy 1, BP 239 54506 Vandoeuvre Cedex, France,
3 Laboratoire de Physico-Chimie des Rayonnements, UMR 8610, Universite Paris XI, Building 350, centre Universitaire 91405 Orsay Cedex, France
The ease of disulfide bond cleavage in peptides and proteins is evaluated by an experimental method (one-electron reduction by COO·- radicals and measurement of the chain length) and two theoretical approaches based on quantum chemistry and topology. All results agree to show acidcatalysis of this bond opening. The disulfide bond in the radical state is weakened by protonation.