An interconversion reaction between thiols (SH) and disulfides (SS) is an important element in antioxidative functions of biological systems as well as oxidative folding of SS-containing proteins. To control these reaction systems, a new water-soluble selenoxide (DHSox) with a five-membered ring has been developed as a highly strong and selective oxidant for thiol (SH) substrates. In this study, the SS formation behaviors in a polypeptide chain by using DHSox were investigated. When the reduced polypeptides, which have several SH groups, were reacted with DHSox, rapid and quantitative SS formation was observed in an aqueous medium. The kinetic analysis showed that the rate constants are proportional to the number of the free SH groups in the reactant, indicating that the SS fomation progresses in a stochastic manner. Ab initio calculation for the energetic landscape showed the presence of a reactive thioselenulane (Se�S) intermediate during the SS formation reaction.

Observation of the SS formation behaviors in a polypeptide chain by using a water-soluble selenoxide reagent with high redox potential

244th National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.