Thiol catalysis of selenosulfide bond cleavage by a triarylphosphine

Abstract

The arylthiol 4-mercaptophenylacetic acid (MPAA) is a powerful catalyst of selenosulfide bond reduction by the triarylphosphine 3,3′,3′′-phosphanetriyltris(benzenesulfonic acid) trisodium salt (TPPTS). Both reagents are water-soluble at neutral pH and are particularly adapted for working with unprotected peptidic substrates. Contrary to trialkylphosphines such as tris(2-carboxyethyl)phosphine hydrochloride (TCEP), TPPTS has the advantage of not inducing deselenization reactions. We believe that the work reported here will be of value for those manipulating selenosulfide bonds in peptidic or protein molecules.

Thiol Catalysis of Selenosulfide Bond Cleavage by a Triarylphosphine

“…Considering the large excesses of thiol additive usually needed for catalyzing NCL, we also examined if their presence has any role in the SetCys conversion into Cys. The studied thiols, MPAA, MTG, and MPSNa, cover by their p K a the range of thiols used for NCL catalysis …”