biostudies-literatureWright TADivision of ChemistryMiami UniversityNational Institute of General Medical SciencesNIGMS NIH HHS2447-2456https://www.ebi.ac.uk/biostudies/studies/S-EPMC9099401biostudies-literatureUnknown32(11)Site-specific conjugation to cysteines of proteins often uses ester groups to link maleimide or alkene groups to polymers. However, the ester group is susceptible to hydrolysis, potentially losing the benefits gained through bioconjugation. Here, we present a simple conjugation strategy that utilizes the amide bond stability of traditional 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide coupling while introducing site specificity. Hydrolytically stable maleimide-end-functionalized polymers for site-specific conjugation to free cysteines of proteins were synthesized using reversible addition-fragmentation chain-transfer (RAFT) polymerization. The alpha terminus of the polymers was amidated with a furan-protected aminoethyl maleimide using carbodiimide-based chemistry. FinBioconjugate chemistryHydrolytically Stable Maleimide-End-Functionalized Polymers for Site-Specific Protein Conjugation.PMC9099401R35 GM1285951460862Page RCTyler AFischesser HJohnson MRBennett CRahman MSKonkolewicz DRam NWright TAfalseHydrolytically Stable Maleimide-End-Functionalized Polymers for Site-Specific Protein Conjugation.Site-specific conjugation to cysteines of proteins often uses ester groups to link maleimide or alkene groups to polymers. However, the ester group is susceptible to hydrolysis, potentially losing the benefits gained through bioconjugation. Here, we present a simple conjugation strategy that utilizes the amide bond stability of traditional 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide coupling while introducing site specificity. Hydrolytically stable maleimide-end-functionalized polymers for site-specific conjugation to free cysteines of proteins were synthesized using reversible addition-fragmentation chain-transfer (RAFT) polymerization. The alpha terminus of the polymers was amidated with a furan-protected aminoethyl maleimide using carbodiimide-based chemistry. Fin2021-01-01T00:00:00Z2021 Nov2025-04-25T23:31:29.966Z2025-04-06T09:26:09.781ZS-EPMC90994013473095410.1021/acs.bioconjchem.1c00487