SITS Derivatization of Peptides to Enhance 266 nm Ultraviolet Photodissociation (UVPD)

M Montana Quick; M Rachel Mehaffey; Robert W Johns; W Ryan Parker; Jennifer S Brodbelt

doi:10.1007/s13361-017-1650-y

SITS Derivatization of Peptides to Enhance 266 nm Ultraviolet Photodissociation (UVPD)

J Am Soc Mass Spectrom. 2017 Jul;28(7):1462-1472. doi: 10.1007/s13361-017-1650-y. Epub 2017 Mar 17.

Authors

M Montana Quick¹, M Rachel Mehaffey¹, Robert W Johns^{2

3}, W Ryan Parker¹, Jennifer S Brodbelt⁴

Affiliations

¹ Department of Chemistry, University of Texas, Austin, TX, 78712, USA.
² Department of Chemistry, University of California, Berkeley, CA, 94720, USA.
³ McKetta Department of Chemical Engineering, University of Texas, Austin, TX, 78712, USA.
⁴ Department of Chemistry, University of Texas, Austin, TX, 78712, USA. jbrodbelt@cm.utexas.edu.

PMID: 28315237
DOI: 10.1007/s13361-017-1650-y

Abstract

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.

Keywords: Derivatization; Ion activation; Peptide; Ultraviolet photodissociation.