Thiol Chemistry

Learning Center – Thiol Alkylators

Thiol blockers, typically iodoacetamide (IAM) or N-ethylmaleimide (NEM), are utilized in numerous redox analytical workflows to prevent oxidative artifacts during specimen processing and to stabilize oxidative modification at cysteine residues which would otherwise react with the reduced cysteines (e.g., resolution of -SOH into disulfides, thiol-disulfide shuffling,  and other thiol-mediated reactions). Earlier work by Reisz et al 1 discovered the lack of selectivity of IAM, NEM, and other reagents towards reduced thiols (-SH) due to the cross-reaction with sulfenylated cysteines (-SOH). This has led to new research and the discovery of MSTP (4-(5-(methylsulfonyl)-1H-tetrazol-1-yl)phenol) [link to compound in market place] as a new cell membrane permeable thiol-selective reagent 2.

Thiol Science

1 Reisz JA, Bechtold E, King SB, Poole LB, Furdui CM. Thiol-blocking electrophiles interfere with labeling and detection of protein sulfenic acids. FEBS J. 2013 Dec;280(23):6150-61. Epub 2013 Oct 16. PMID: 24103186; PMCID: PMC3928805.

2 Chen X, Wu H, Park CM, Poole TH, Keceli G, Devarie-Baez NO, Tsang AW, Lowther WT, Poole LB, King SB, Xian M, Furdui CM. Discovery of Heteroaromatic Sulfones As a New Class of Biologically Compatible Thiol-Selective Reagents. ACS Chem Biol. 2017 Aug 18;12(8):2201-2208. Epub 2017 Jul 19. PMID: 28687042; PMCID: PMC5658784.


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