This reagent can be used to block thiols (SH) in proteins and peptides containing cysteine residues, as well as other thiolated molecules (such as thiol-containing oligonucleotides) at room temperature. Free thiols are converted to SSCys residues and an equivalent of PhSO- are produced.
Highlights:
The thiosulfonate switch technique traps protein S-nitrosothiols as mixed disulfides bearing a fluorescent probe at pH 4.0. The protocol involves initial blocking of protein thiols by S-phenylsulfonylcysteine (SPSC), which forms cysteine bearing mixed disulfides. The byproduct of the initial blocking step is benzenesulfinate itself. Subsequent addition of PhSO2Na converts protein S-nitrosothiols into protein S-phenylthiosulfonates. Addition of a highly water soluble zwitterionic rhodamine based fluorophore incorporating a reactive thiol, denoted Z-Rhodamine-SH, reacts with protein S-phenylthiosulfonates, giving rise to a mixed disulfide between the probe and the formerly S-nitrosated cysteine residue.
Also available: Z-Rhodamine-SH
From the laboratory of Paul A. Grieco, PhD, Montana State University.
Part of The Investigator's Annexe program.
Product Type: | Small Molecule |
Name: | S-phenylsulfonylcysteine (SPSC) |
Chemical Formula: | C9H11NO4S2 |
Molecular Weight: | 261.31 |
Format: | White powder |
Purity: | 95+% (NMR) |
Solubility: | Good in water and polar organic solvents |
Comments: | Do not store this reagent in water |
Storage: | -20C. Protect from light. Dessicate |
Shipped: | Cold packs |
Conversion of SPSC
% Conversion of SPSC to PhSO2Na over 1h as measured from absorbance detection at 265 nm from RP HPLC analysis.
Adapted from: Reeves BD, et al. Org Biomol Chem. 2014 Oct 28;12(40):7942-56.
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