Graphical abstract

Tuning the properties of maleimide reagents holds significant promise in expanding the toolbox of available methods for bioconjugation. Herein we describe aryloxymaleimides which represent 'next generation maleimides' of attenuated reactivity, and demonstrate their ability to enable new methods for protein modification at disulfide bonds.

The most widely cited procedures for radiolabeling antibodies with zirconium-89 for immuno-PET require multi-milligram amounts of antibody which can be cost-prohibitive, particularly during the research and development process. We therefore sought to develop a reliable (89)Zr-radiolabeling procedure that provides high radiochemical yields at the microgram scale.