Identification of formylglycine in sulfatases by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

✍ Scribed by Jianhe Peng; Bernhard Schmidt; Kurt von Figura; Thomas Dierks

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 782 KB
• Volume: 38
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/jms.404

✦ Synopsis

Abstract

C~α~‐Formylglycine, the catalytic amino acid residue in the active site of sulfatases, is generated by post‐translational modification of a cysteine or serine residue. We describe a highly sensitive procedure for the detection of C~α~‐formylglycine‐containing peptides in tryptic digests of sulfatase proteins. The protocol is based on the formation of hydrazone derivatives of C~α~‐formylglycine‐containing peptides when using dinitrophenylhydrazine as a matrix for matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS). The hydrazone derivatives desorb and ionize with high efficiency and can be detected in the sub‐femtomole range. The presence of C~α~‐formylglycine is indicated by a mass increment of 180.13 u, corresponding to the hydrazone moiety, and also by a unique C‐terminal fragment ion, characteristic of sulfatases, that becomes prominent in MALDI post‐source decay mass spectra of the hydrazone derivatives. Copyright © 2003 John Wiley & Sons, Ltd.