Journal article

Establishing Signature Fragments for Identification and Sequencing of Dityrosine Cross-Linked Peptides Using Ultraviolet Photodissociation Mass Spectrometry

Soumya Mukherjee, Mengxuan Fang, W Mei Kok, Eugene A Kapp, Varsha J Thombare, Romain Huguet, Craig A Hutton, Gavin E Reid, Blaine R Roberts

ANALYTICAL CHEMISTRY | AMER CHEMICAL SOC | Published : 2019

Abstract

Dityrosine cross-linking of Aβ peptides and α-synuclein is increasingly becoming recognized as a biomarker of neuropathological diseases. However, there remains a need for the development of analytical methods that enable the specific and selective identification of dityrosine cross-linked proteins and peptides in complex biological samples. Here, we report that the gas-phase fragmentation of protonated dityrosine cross-linked peptides under ultraviolet photodissociation (UVPD) tandem mass spectrometry (MS/MS) conditions results in the cleavage across Cα and Cβ atoms of the dityrosine residue. This Cα-Cβ cleavage in UVPD-MS/MS results in the formation of diagnostic pairs of product ions, pro..

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