Resonant dissociative electron attachments to cysteine and cystine.

Shape-resonant electron attachments to cysteine and cystine and the subsequent dissociation dynamics are investigated with the single-center expansion potential scattering calculations. Selectivity of the direct bond cleavage at a given resonant state or by the specific resonant state coupling is demonstrated with the one-dimensional complex potential energy curves of the temporary anion (cysteine)(-). The wave function of the lowest shape resonant state of the temporary anion (cystine)(-) distinctly shows the localized anti-bond (S-S)* character, implying that this disulfide bond can be easily broken due to the low-energy electron resonant attachment.