Detection of Thiol Functionality and Disulfide Bond Formation by Polyoxometalate

Abstract

The detection of thiol functionality and intramolecular disulfide bond formation of peptides using the α-Keggin type polyoxometalate molybdenum−oxygen cluster (H 3 PMo 12 O 40 •nH 2 O) is described. Our method entails the addition of this polyoxometalate to solutions of thiol, whereupon the color of the solution changes from colorless to deep blue. Reduction of the polyoxometalate from Mo(VI) to Mo(V) occurs with concomitant oxidation of the thiol functionality, to form disulfide bonds. To exemplify the utility this phenomenon, we accomplished the oxidation of glutathione, reduced linear oxytocin, bactenecin, and α-conotoxin SI; all of which proceeded smoothly and in good conversion in 24 h to less and were accomplished by a change in the color of the reaction solutions.

Expanding the Toolbox for Peptide Disulfide Bond Formation via l-Methionine Selenoxide Oxidation

“…Air oxidation, oxidation using dimethyl sulfoxide, and iodine oxidation have been widely applied for the construction of disulfide bonds in peptides. − The limitations of these methods include low oxidation yield, slow reaction rate, over-oxidation of the thiol group, and side reactions on the Met, Tyr, and Trp residues. In order to develop a methodology for the preparation of peptide disulfides, some new oxidants including N -chlorosuccinimide, 3-nitro-2-pyridinesulfenates, disulfiram, and polyoxometalate molybdenum-oxygen clusters have been developed. − …”

Synergistic TME-manipulation effects of a molybdenum-based polyoxometalate enhance the PTT effects on cancer cells

“…2a) gradually with the concentration. This indicates that more Mo(VI) reduction to Mo(V) by cysteine leads to the improved electron transition numbers from Mo(V) to Mo(VI), 44,45 thereby increasing the absorbance of [Mo 154 ] at 808 nm. Besides, at a fixed amount of cysteine, A 808 changed with incubation time (Fig.…”

Real-time imaging of sulfhydryl single-stranded DNA aggregation

“…However, the process and mechanism of disulfide bond formation and rearrangement in biomacromolecules need to be explored. Many technologies, including atomic force microscopy, computer simulation, and chemical color-reaction method, have been used to study disulfide bond formation and rearrangement 7 – 10 . For the absence of real-time imaging of the dynamic process at nanoscale, detailed information on the structural changes and rearrangement induced by disulfide bonds is lacking.…”