An innovative strategy for sulfopeptides analysis using MALDI-TOF MS reflectron positive ion mode.
Sulfation of tyrosine residues is a key posttranslational modification in the regulation of various cellular processes. As such, the detection and localization of tyrosine sulfation is an essential step toward the elucidation of the physiological and pathological roles of this process. Despite substantial advances, intact sulfated peptides are still difficult to detect by MALDI-MS due to the extreme lability of the sulfo-moiety. The present report demonstrates for the first time how intact sulfated peptides can be directly and specifically detected by MALDI-MS in positive reflectron mode by using pyrenemethylguanidine (pmg) as a noncovalent derivatizing agent and an ionization enhancer. This new method allows the determination of the degree of sulfation of sulfopeptides pure or in mixtures. Moreover, the observation of specific peaks in the mass spectra enables a rapid and unambiguous discrimination between phospho- and sulfopeptides.
Institut des Biomolécules Max Mousseron, UMR 5247 CNRS-Université Montpellier 1 et 2, Montpellier, France.
Sonia
S
Cantel
Luc
L
Brunel
Keiichiro
K
Ohara
Christine
C
Enjalbal
Jean
J
Martinez
Jean-Jacques
JJ
Vasseur
Michael
M
Smietana
D000818:Animals; D002417:Cattle; D006801:Humans; D008760:Methylguanidine / Q000031:analogs & derivatives / Q000737:chemistry; D010446:Peptide Fragments / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D010748:Phosphopeptides / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011506:Proteins / Q000032:analysis* / Q000737:chemistry; D011721:Pyrenes / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013431:Sulfates / Q000032:analysis / Q000737:chemistry; D014357:Trypsin / Q000378:metabolism; D014443:Tyrosine / Q000032:analysis / Q000737:chemistry / Q000378:metabolism
D010446:Peptide Fragments; D010748:Phosphopeptides; D011506:Proteins; D011721:Pyrenes; D013431:Sulfates; D014443:Tyrosine; D008760:Methylguanidine; C030984:pyrene; D014357:Trypsin