English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In vitro analysis of covalent inhibitors requires special consideration, due to the time-dependent and typically irreversible nature of their target interaction. While many analyses are reported for the characterization of a final candidate, it is less clear which are most useful in the lead optimization phase of drug discovery. In the context of identifying covalent inhibitors of Bruton's tyrosine kinase (BTK), we evaluated multiple techniques for characterizing covalent inhibitors. Several methods qualitatively support the covalent mechanism of action or support a particular aspect of interaction but were not otherwise informative to differentiate inhibitors. These include the time dependence of IC 50 , substrate competition, mass spectrometry, and recovery of function after inhibitor removal at the biochemical and cellular level. A change in IC 50 upon mutation of the targeted BTK C481 nucleophile or upon removal of the electrophilic moiety of the inhibitor was not always a reliable indicator of covalent inhibition. Determination of k inact and K I provides a quantitative description of covalent interactions but was challenging at scale and frequently failed to provide more than the ratio of the two values, k inact /K I . Overall, a combination of approaches is required to assess time-dependent, covalent, and irreversible inhibitors in a manner suitable to reliably advance drug candidates.

Merits and Pitfalls in the Characterization of Covalent Inhibitors of Bruton’s Tyrosine Kinase