Late-stage functionalization with strain-release warheads enables tunable covalent inhibition

Z Zachary P. Shultz (Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.) A Ansar Lee-Sam (Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.) Y Yun-Pu Chang (Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.) L Luxin Sun (Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.) D Dylan Grassie (Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.) A Alessio Gabellini (Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.) K Kyle Pedretty (Department of Chemistry, University of South Florida, Tampa, FL, USA.) T Thomas Scattolin (Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.) V Victoria Izumi (Proteomics and Metabolomics Core, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.) B Bin Fang (Proteomics and Metabolomics Core, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.) S Samer Sansil (Cancer Pharmacokinetics and Pharmacodynamics Core, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.) R Ramu Kakumanu (Cancer Pharmacokinetics and Pharmacodynamics Core, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.) L Lukasz Wojtas (Department of Chemistry, University of South Florida, Tampa, FL, USA.) J John Koomen (Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.) E Ernst Schönbrunn (Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.) A Andrii Monastyrskyi (Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.) D Derek Duckett (Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.) J Justin M. Lopchuk (Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.)

Abstract

Covalent inhibition continues to gain momentum as a strategy for selective protein modulation in both therapeutic and chemical biology contexts. Covalent reactive groups (CRGs) typically engage nucleophilic residues such as cysteine, resulting in targeted protein inactivation. However, common electrophiles such as acrylamides often suffer from nonselective reactivity, leading to off-target effects and toxicity. To overcome these limitations, we developed a modular sulfur(IV) reagent platform for the mild, late-stage installation of sulfonyl- and sulfonimidoyl-bicyclobutane motifs with complete cysteine selectivity. This methodology enables access to diverse sulfur(VI) CRGs with tunable strain-release reactivity. Incorporation into US Food and Drug Administration–approved covalent inhibitors demonstrated effective bioisosteric replacement of acrylamides and the potential of strain-release CRGs for selective protein targeting. Preclinical studies in mice have validated this approach, highlighting its promise for next-generation covalent drug design.

Article Details

Journal Science
Volume / Issue Vol. 393, Issue 6809
Published July 23, 2026
Pages 408-416
ISSN 0036-8075
Publisher American Association for the Advancement of Science

Journal Info

Science

American Association for the Advancement of Science

ISSN: 0036-8075 Social Sciences

Authors (18)

Z

Zachary P. Shultz

Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.

A

Ansar Lee-Sam

Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.

Y

Yun-Pu Chang

Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.

L

Luxin Sun

Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.

D

Dylan Grassie

Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.

A

Alessio Gabellini

Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.

K

Kyle Pedretty

Department of Chemistry, University of South Florida, Tampa, FL, USA.

T

Thomas Scattolin

Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.

V

Victoria Izumi

Proteomics and Metabolomics Core, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.

B

Bin Fang

Proteomics and Metabolomics Core, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.

S

Samer Sansil

Cancer Pharmacokinetics and Pharmacodynamics Core, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.

R

Ramu Kakumanu

Cancer Pharmacokinetics and Pharmacodynamics Core, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.

L

Lukasz Wojtas

Department of Chemistry, University of South Florida, Tampa, FL, USA.

J

John Koomen

Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.

E

Ernst Schönbrunn

Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.

A

Andrii Monastyrskyi

Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.

D

Derek Duckett

Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.

J

Justin M. Lopchuk

Drug Discovery Department, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.