title: Naphthalimide Scaffold Provides Versatile Platform for Selective Thiol Sensing and Protein Labeling.
abstract: Reversible thiol modifications are fundamental of cellular redox regulation. Specific thiol detection, including thiol sensing and protein thiols labeling, is critical to study such modifications. We reported the discovery of 4-methylsulfonyl-N-n-butyl-1,8-naphthalimide (MSBN), a highly selective fluorogenic probe for thiols based on the 1,8-naphthalimide scaffold. Thiols react with MSBN nearly quantitatively via nucleophilic aromatic substitution to replace the methylsulfonyl group and restore the quenched fluorescence (>100-fold increase). MSBN was employed to selectively image thiols in live cells and specifically label protein thiols with a turn-on signal to determine diverse reversible protein thiol modifications. In addition, we introduced a bulky group into the MSBN as a mass tag to create a probe MSBN-TPP, which readily discriminates the reduced thioredoxin from the oxidized one. The specific reaction of MSBN with thiols and the easy manipulation of the naphthalimide unit enable MSBN a versatile scaffold in developing novel probes for thiol-based protein bioconjugation and studying various thiol modifications.
authors.affiliation: State Key Laboratory of Applied Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University , Lanzhou 730000, China.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Applied Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University , Lanzhou 730000, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Yao
authors.affiliation: State Key Laboratory of Applied Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University , Lanzhou 730000, China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Applied Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University , Lanzhou 730000, China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Fang
mesh_terms: D006801:Humans; D053644:Naphthalimides / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000378:metabolism*
chemical_list: D053644:Naphthalimides; D011506:Proteins; D013438:Sulfhydryl Compounds