A novel SPE-UPLC-MS/MS-based assay for the selective, simultaneous quantification of xylosyltransferase-I and -II activity

Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved..

Xylosyltransferase-I and -II (XT-I, -II) possess a central role during the glycosylation of proteoglycans (PGs). They catalyze the formation of an O-glycosidic bond between the xylosyl residue of uridinediphosphate-xylose and the core protein of a PG. Thereafter, three following glycosyltransferases lead to the generation of a tetrasaccharide linker, which connects the PG core protein to the respective glycosaminoglycan. The selective quantification of XT-I and XT-II activity is of biological and clinical interest due to their association with fibrotic processes and skeletal dysplasia. There is no assay available to date that simultaneously determines the activity of the two XT isoforms. Although an XT-I selective UPLC MS/MS-based assay was published by Fischer et al., in 2021, the determination of XT-II activity can only be performed simultaneously by the improved assay presented here. To establish the assay, two synthetic peptides, selectively xylosylated by the respective isoform, were identified and the associated measurement parameters for the mass spectrometer were optimized. In addition, the quantitative range of the xylosylated peptides were validated, and the incubation time of the enzyme reaction was optimized for cell culture samples and human sera. The specific enzyme kinetics (KM and Vmax) of the respective XT isoform for the two peptides were also determined. Subsequently, a mathematical model was developed, allowing the simultaneous determination of XT-I and XT-II activity from the chromatographic results. Summarized, a mass spectrometric method suitable for the simultaneous analysis of XT-I and XT-II activity in cell culture lysates, supernatants and human sera was successfully developed.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:218

Enthalten in:

Biochimie - 218(2024) vom: 23. Feb., Seite 127-136

Sprache:

Englisch

Beteiligte Personen:

Kleine, Anika [VerfasserIn]
Kühle, Matthias [VerfasserIn]
Kuhn, Joachim [VerfasserIn]
Ly, Thanh-Diep [VerfasserIn]
Schmidt, Vanessa [VerfasserIn]
Faust-Hinse, Isabel [VerfasserIn]
Knabbe, Cornelius [VerfasserIn]
Fischer, Bastian [VerfasserIn]

Links:

Volltext

Themen:

EC 2.4.2.-
EC 2.4.2.26
Extracellular matrix
Fibrosis
Glycosaminoglycan
Human xylosyltransferase-I and -II
Journal Article
Mass spectrometry
Pentosyltransferases
Peptides
Protein Isoforms
Proteoglycan synthesis
UDP Xylose-Protein Xylosyltransferase

Anmerkungen:

Date Completed 21.02.2024

Date Revised 21.02.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.biochi.2023.09.008

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM361867433