Reversible targeting of noncatalytic cysteines with chemically tuned electrophiles

Iana M. Serafimova, Miles A. Pufall, Shyam Krishnan, Katarzyna Duda, Michael Cohen, Rebecca L. Maglathlin, Jesse M. McFarland, Rand M. Miller, Morten Frödin, Jack Taunton

Research output: Contribution to journalArticle

221 Scopus citations


Targeting noncatalytic cysteine residues with irreversible acrylamide-based inhibitors is a powerful approach for enhancing pharmacological potency and selectivity. Nevertheless, concerns about off-target modification motivate the development of reversible cysteine-targeting strategies. Here we show that electron-deficient olefins, including acrylamides, can be tuned to react with cysteine thiols in a rapidly reversible manner. Installation of a nitrile group increased the olefins' intrinsic reactivity, but, paradoxically, eliminated the formation of irreversible adducts. Incorporation of these electrophiles into a noncovalent kinase-recognition scaffold produced slowly dissociating, covalent inhibitors of the p90 ribosomal protein S6 kinase RSK2. A cocrystal structure revealed specific noncovalent interactions that stabilize the complex by positioning the electrophilic carbon near the targeted cysteine. Disruption of these interactions by protein unfolding or proteolysis promoted instantaneous cleavage of the covalent bond. Our results establish a chemistry-based framework for engineering sustained covalent inhibition without accumulating permanently modified proteins and peptides.

Original languageEnglish (US)
Pages (from-to)471-476
Number of pages6
JournalNature Chemical Biology
Issue number5
Publication statusPublished - May 2012
Externally publishedYes


ASJC Scopus subject areas

  • Cell Biology
  • Molecular Biology

Cite this

Serafimova, I. M., Pufall, M. A., Krishnan, S., Duda, K., Cohen, M., Maglathlin, R. L., ... Taunton, J. (2012). Reversible targeting of noncatalytic cysteines with chemically tuned electrophiles. Nature Chemical Biology, 8(5), 471-476.