Characterization of the Cysteine Content in Proteins Utilizing Cysteine Selenylation with 266 nm Ultraviolet Photodissociation (UVPD).
Characterization of the cysteine content of proteins is a key aspect of proteomics. By defining both the total number of cysteines and their bound/unbound state, the number of candidate proteins considered in database searches is significantly constrained. Herein we present a methodology that utilizes 266 nm UVPD to count the number of free and bound cysteines in intact proteins. In order to attain this goal, proteins were derivatized with N-(phenylseleno)phthalimide (NPSP) to install a selectively cleavable Se-S bond upon 266 UVPD. The number of Se-S bonds cleaved upon UVPD, a process that releases SePh moieties, corresponds to the number of cysteine residues per protein. Graphical Abstract ᅟ.
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
Cysteine; Photodissociation; Selenylation