Orthogonal, dual protein labelling by tandem cycloaddition of strained alkenes and alkynes to ortho-quinones and azides.

Jorick J. Bruins,Floris L. van Delft,Bauke Albada,Vincent van der Doef,Daniel Blanco-Ania

doi:10.1039/c8cc02638f

Abstract

Reaction of cyclopropanated trans-cyclooctene (cpTCO) with in situ generated ortho-quinone is an efficient tool for bioorthogonal protein conjugation. The (4+2)-cycloaddition of cpTCO with ortho-quinone is significantly faster than its cyclooctyne counterpart (BCN). Orthogonal, tandem cpTCO-quinone and BCN-azide cycloadditions afforded a homogeneous, dual labelled antibody-drug conjugate.

Highlights

Reaction of cyclopropanated trans-cyclooctene with in situ generated ortho-quinone is an efficient tool for bioorthogonal protein conjugation
In analogy to our previous work, we studied the alkene–strain-promoted oxidation-controlled ortho-quinone cycloaddition (SPOCQ) reaction between cyclopropanated trans-cyclooctene (cpTCO)–PEG–lissamine and Tras[HC]G4Y upon incubation with mushroom tyrosinase to oxidize the exposed tyrosine phenol ring of the G4Y-tag to ortho-quinone.[19]
We explore the possibility of tandem installation of two different functional moieties onto a glycan-remodelled monoclonal antibody[24] by cpTCO–SPOCQ and BCN–strain-promoted azide–alkyne cycloaddition (SPAAC), executed in either order

Summary

Introduction

Orthogonal, dual protein labelling by tandem cycloaddition of strained alkenes and alkynes to ortho-quinones and azides† Reaction of cyclopropanated trans-cyclooctene (cpTCO) with in situ generated ortho-quinone is an efficient tool for bioorthogonal protein conjugation.

Results

Conclusion