Meta- and para-phenylenediamines have recently been shown to catalyze oxime and hydrazone ligation reactions at rates much faster than aniline, a commonly used catalyst. Here, we demonstrate how these new catalysts can be used in a generally applicable procedure for fluorescent labeling, PEGylation, immobilization, and release of aldehyde- and ketone- functionalized proteins. The chemical orthogonality of phenylenediamine-catalyzed oxime ligation versus copper-catalyzed click reaction has also been harnessed for simultaneous dual labeling of bifunctional proteins containing both aldehyde and alkyne groups in high yield.
Bibliographical notePublisher Copyright:
© 2014 by John Wiley & Sons, Inc.
- Dual protein labeling
- Hydrazone ligation
- Oxime ligation