Exploring the versatility of pentafulvene-maleimide cycloaddition as a ligation strategy: buffer and pH effects.

Ligation chemistries are often required to perform under stringent conditions that preserve the integrity and function of (bio)conjugates, including specific biological buffers. To explore the versatility of the pentafulvene-maleimide ligation for (bio)conjugations, we studied the stability of the coupling partners and their Diels-Alder cycloaddition (DAC) in buffers used commonly in biological assays, protein chemistry and bioconjugates. The stability of 6,6-dialkylpentafulvene and maleimide derivatives to a panel of buffers with pH values between 3.