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Published March 23, 2005 | metadata_only
Journal Article

Cluster-Phase Reactions: Gas-Phase Phosphorylation of Peptides and Model Compounds with Triphosphate Anions


Molecular clusters provide a unique environment in which chemical reactions between cluster components can occur. In the present study, electrospray ionization is used to examine the behavior of anionic clusters of triphosphate with choline, acetylcholine, and betaine, and the behaviors of cationic clusters of triphosphate with the peptides bradykinin (RPPGFSPFR) and ARRPEGRTWAQPGY. Phosphorylation of a hydroxyl group, when one is present, is shown to be a facile process when the cluster is subjected to collisional activation. Of particular interest is the selective phosphorylation of the hydroxyl substituent in serine and threonine residues of peptides. Less conclusive results are obtained with three peptides containing tyrosine, but the data obtained are consistent with phosphorylation on tyrosine residues. In the absence of residues with hydroxyl substituents, the C-terminus of a peptide is observed to be phosphorylated. The unique chemical reactions reported in this study represent the first examples of gas-phase phosphorylation of alcohols and are also interesting in that they occur at a site remote from charged functional groups in the same molecule. This facile process may have interesting implications for the synthesis of key molecules at the threshold of life.

Additional Information

© 2005 American Chemical Society. Received August 5, 2004. Publication Date (Web): February 25, 2005. We thank Dr. Mona Shagoli for use of the Mass Spectrometry facility, as well as the Director's Research and Development Fund at the Jet Propulsion Laboratory and the Beckman Institute for funding. Support for studies of chemistry at the threshold of life is provided by NASA under ASTID NASA-Goddard Grant No. NNG04GJ00G. This material is based upon work supported by the National Science Foundation under Grant No. CHE-0416381.

Additional details

August 19, 2023
August 19, 2023