Palladium reagents – chemicals once thought to be exclusively used in organic synthesis – can be used to couple small molecules onto proteins

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Professor Alexander Spokoyny is co-author of the paper describing the research recently published in the prestigious journal Nature.

The paper describes the research team’s development of a reaction that selectively adds aryl groups to free cysteine residues in proteins. The reaction can be used to make myriad modified proteins, including therapeutic antibody-drug conjugates.

Titled “Organometallic palladium reagents for cysteine bioconjugation”, the paper was published in the October 29th issue of Nature.

The research was highlighted by UCLA Professor Heather Maynard in a letter titled “Chemical biology: Protein modification in a trice” published on-line in Nature on Oct. 28th.

The Nature paper was also highlighted Nov. 2nd issue of Chemical and Engineering News (C&EN) in an article titled “Organometallics Add Aryl Groups To Proteins Selectively“. Prof. Maynard, an expert in protein conjugation chemistry, is quoted in the article regarding the reaction – “I think it’s a very powerful strategy. It’s high yielding, it’s fast, and the fact that it has a relatively stable bond compared to other chemistry makes this reaction very exciting”. The article went on to say that Prof. Maynard expects that biochemists will be more likely to adopt the technique if they don’t have to make the reagents but can buy them in a kit instead.

A palladium complex tacks the anticancer drug vandetanib (red) onto the free cysteine residue of an antibody (blue).

The co-authors on the study are all from the Massachusetts Institute of Technology (MIT) Department of Chemistry: Ekaterina V. Vinogradova, Chi Zhang, Professor Bradley L. Pentelute, and Professor Stephen L. Buchwald.

Prof. Spokoyny was a postdoctoral researcher in the Buchwald and Pentelute laboratories at MIT before joining the faculty at UCLA.

To learn more about Prof. Spokoyny’s research, visit his group’s website.

Figure from C&EN