Premium
Identification of by‐products from an orthogonal peptide ligation by oxime bonds using mass spectrometry and tandem mass spectrometry
Author(s) -
Buré Corinne,
Lelièvre Dominique,
Delmas Agnès
Publication year - 2000
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/1097-0231(20001215)14:23<2158::aid-rcm147>3.0.co;2-c
Subject(s) - chemistry , mass spectrometry , tandem mass spectrometry , oxime , protein mass spectrometry , tandem mass tag , top down proteomics , chromatography , selected reaction monitoring , tandem , proteomics , organic chemistry , biochemistry , quantitative proteomics , materials science , composite material , gene
Synthetic proteins with unusual architecture are obtained through chemoselective ligation, a method based on the condensation of unprotected peptides under mild aqueous conditions. The last step of a new procedure leading to a tri‐branched conjugate consists of the chemoselective ligation reaction between an (aminooxy)acetyl peptide and a peptide aldehyde resulting from a first ligation via an oxime bond. In order to optimize the reaction conditions, electrospray ionization mass spectrometry combined with liquid chromatography and tandem mass spectrometry has been used. In addition to the target tri‐branched conjugate, two other conjugates were characterized allowing documentation of transoximation reactions in peptide chemistry. A fourth conjugate was identified as a side product appearing after the first ligation. Data obtained by low‐energy collision‐induced dissociation led to a rapid and reliable identification of impurities observed in the (aminooxy)acetyl peptide despite a previous high performance liquid chromatography (HPLC) purification. This highlights the great reactivity of the aminooxy group towards carbonyl‐containing compounds. Copyright © 2000 John Wiley & Sons, Ltd.