Open AccessTunable Methacrylamides for Covalent Ligand Directed Release Chemistry
Author(s) -
Rambabu Reddi,
Efrat Resnick,
Adi Rogel,
Boddu Venkateswara Rao,
Ronen Gabizon,
Kim Goldenberg,
Neta Gurwicz,
Daniel Zaidman,
A.N. Plotnikov,
Haim Barr,
Ziv Shulman,
Nir London
Publication year - 2021
Publication title -
journal of the american chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.115
H-Index - 612
eISSN - 1520-5126
pISSN - 0002-7863
DOI - 10.1021/jacs.0c10644
Subject(s) - chemistry , covalent bond , electrophile , combinatorial chemistry , cysteine , conjugate , ligand (biochemistry) , substituent , bruton's tyrosine kinase , reactivity (psychology) , bioconjugation , stereochemistry , biochemistry , organic chemistry , tyrosine kinase , enzyme , signal transduction , receptor , medicine , mathematical analysis , mathematics , alternative medicine , pathology , catalysis
Targeted covalent inhibitors are an important class of drugs and chemical probes. However, relatively few electrophiles meet the criteria for successful covalent inhibitor design. Here we describe α-substituted methacrylamides as a new class of electrophiles suitable for targeted covalent inhibitors. While typically α-substitutions inactivate acrylamides, we show that hetero α-substituted methacrylamides have higher thiol reactivity and undergo a conjugated addition-elimination reaction ultimately releasing the substituent. Their reactivity toward thiols is tunable and correlates with the p K a /p K b of the leaving group. In the context of the BTK inhibitor ibrutinib, these electrophiles showed lower intrinsic thiol reactivity than the unsubstituted ibrutinib acrylamide. This translated to comparable potency in protein labeling, in vitro kinase assays, and functional cellular assays, with improved selectivity. The conjugate addition-elimination reaction upon covalent binding to their target cysteine allows functionalizing α-substituted methacrylamides as turn-on probes. To demonstrate this, we prepared covalent ligand directed release (CoLDR) turn-on fluorescent probes for BTK, EGFR, and K-Ras G12C . We further demonstrate a BTK CoLDR chemiluminescent probe that enabled a high-throughput screen for BTK inhibitors. Altogether we show that α-substituted methacrylamides represent a new and versatile addition to the toolbox of targeted covalent inhibitor design.