Open AccessInvestigation of the Experimental Parameters of Ultraviolet Photodissociation for the Structural Characterization of Chondroitin Sulfate Glycosaminoglycan Isomers
Author(s) -
Lauren E. Pepi,
Franklin E. Leach,
Dustin R. Klein,
Jennifer S. Brodbelt,
I. Jonathan Amster
Publication year - 2021
Publication title -
journal of the american society for mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.961
H-Index - 127
eISSN - 1879-1123
pISSN - 1044-0305
DOI - 10.1021/jasms.1c00119
Subject(s) - chemistry , sulfation , dermatan sulfate , chondroitin sulfate , chondroitin , glycosaminoglycan , photodissociation , uronic acid , mass spectrometry , sulfate , polysaccharide , stereochemistry , chromatography , biochemistry , photochemistry , organic chemistry
Glycosaminoglycans (GAGs) are linear polysaccharides that participate in a broad range of biological functions. Their incomplete biosynthesis pathway leads to nonuniform chains and complex mixtures. For this reason, the characterization of GAGs has been a difficult hurdle for the analytical community. Recently, ultraviolet photodissociation (UVPD) has emerged as a useful tool for determining sites of modification within a GAG chain. Here, we investigate the ability for UVPD to distinguish chondroitin sulfate epimers and the effects of UVPD experimental parameters on fragmentation efficiency. Chondroitin sulfate A (CS-A) and chondroitin sulfate B (CS-B), commonly referred to as dermatan sulfate (DS), differ only in C-5 uronic acid stereochemistry. This uronic acid difference can influence GAG-protein binding and therefore can alter the specific biological function of a GAG chain. Prior tandem mass spectrometry methods investigated for the elucidation of GAG structures also have difficulty differentiating 4- O from 6- O sulfation in chondroitin sulfate GAGs. Preliminary data using UVPD to characterize GAGs showed a promising ability to characterize 4- O sulfation in CS-A GAGs. Here, we look in depth at the capability of UVPD to distinguish chondroitin sulfate C-5 diastereomers and the role of key experimental parameters in making this distinction. Results using a 193 nm excimer laser and a 213 nm solid-state laser are compared for this study. The effect of precursor ionization state, the number of laser pulses (193 or 213 nm UVPD), and the use of the low-pressure versus high-pressure trap are investigated.