SITS Derivatization of Peptides to Enhance 266 nm Ultraviolet Photodissociation (UVPD).
N-terminal derivatization of peptides with the chromogenic reagent 4-acetamido-4-isothiocyanatostilbene-2,2-disulfonic acid (SITS) is demonstrated to enhance the efficiency of 266 nm ultraviolet photodissociation (UVPD). Attachment of the chromophore results in a mass shift of 454 Da and provides significant gains in the number and abundances of diagnostic fragment ions upon UVPD. Activation of SITS-tagged peptides with 266 nm UVPD leads to many fragment ions akin to the a/b/y ions commonly produced by CID, along with other sequence ions (c, x, and z) typically accessed through higher energy pathways. Extreme bias towards C-terminal fragment ions is observed upon activation of SITS-tagged peptides using multiple 266 nm laser pulses. Due to the high reaction efficiency of the isothiocyanate coupling to the N-terminus of peptides, we demonstrate the ability to adapt this strategy to a high-throughput LC-MS/MS workflow with 266 nm UVPD. Graphical Abstract ᅟ.
Department of Chemistry, University of Texas, Austin, TX, 78712, USA.
M Montana
MM
Quick
Department of Chemistry, University of Texas, Austin, TX, 78712, USA.
M Rachel
MR
Mehaffey
Department of Chemistry, University of California, Berkeley, CA, 94720, USA.|McKetta Department of Chemical Engineering, University of Texas, Austin, TX, 78712, USA.
Robert W
RW
Johns
Department of Chemistry, University of Texas, Austin, TX, 78712, USA.
W Ryan
WR
Parker
Department of Chemistry, University of Texas, Austin, TX, 78712, USA. jbrodbelt@cm.utexas.edu.
Jennifer S
JS
Brodbelt
Derivatization; Ion activation; Peptide; Ultraviolet photodissociation