Thermo Scientific Pierce MMTS (methyl methanethiosulfonate) is a small compound that reversibly blocks cysteines and other sulfhydryl groups, enabling the study of enzyme activation and other protein functions.
MMTS (methyl methanethiosulfonate) is a sulfhydryl-reactive compound that can reversibly sulfenylate thiol-containing molecules. Reacting MMTS with reduced sulfhydryls (-SH) results in their modification to dithiomethane (-S-S-CH3). Treatment with reducing agents, such as dithiothreitol (DTT), 2-mercaptoethanol (2-ME) or Tris(2-carboxyethyl) phosphine hydrochloride (TCEP), will cleave the disulfide groups to restore the original sulfhydryl. MMTS is commonly used to study biochemical pathways involving thiol-dependent enzymes.
- Converts sulfhydryl groups on cysteine side chains into -S-S-CH3
- Reaction is reversible with DTT or TCEP, restoring the free sulfhydryl
- Used to modify thiol groups in creatine kinase
Structure and properties of MMTS:
- Chemical name: methyl methanethiosulfonate
- Reactivity: sulfhydryl groups (adds methyl group via disulfide bond)
- Chemical formula: C2H6O2S2
- CAS number: 2949-92-0
- Molecular weight: 126.20
- Form: liquid
- Boiling point: 85-87°C/0.8mm
- Kirley, T.L. (1989). Reduction and fluorescent labeling of cyst(e)ine-containing proteins for subsequent structural analyses. Anal Biochem 180:231.
- Smith, D.J., et al. (1975). Simple alkanethiol groups for temporary blocking of enzymes. Biochemistry 14:766.
Overview of crosslinking and protein modification
S-nitrosylation Western Blot Kit (protocol uses MMTS)
Iodoacetamide – carboxymethylate sulfhydryls
N-ethylmaleimide – permanently block sulfhydryls
MM(PEG)n – methylate and pegylate sulfhydryls