Electron capture dissociation of the disulfide bond—a quantum chemical model study

• DOI: 10.1016/j.ijms.2004.01.020
• Publication Date: 2004-04-28T18:07:34Z
• Authors: Einar Uggerud
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract Four possible mechanism for ECD of disulfide bonds have been assessed using quantum chemical methods (B3LYP, G2, CASSCF and QCISD). For protonated peptides and proteins interacting with zero-energy electrons, the two most likely mechanisms appear to be either spontaneous dissociation of the SS bond upon impact of a slowly moving free hydrogen or induced by uptake of a nascent hydrogen radical initially in close contact through a hydrogen bond.