Advanced

Exploration of the active site of β4GalT7: modifications of the aglycon of aromatic xylosides.

Siegbahn, Anna; Thorsheim, Karin; Ståhle, Jonas; Manner, Sophie; Hamark, Christoffer; Persson, Andrea LU ; Tykesson, Emil LU ; Mani, Katrin LU ; Westergren-Thorsson, Gunilla LU and Widmalm, Göran, et al. (2015) In Organic and Biomolecular Chemistry 13(11). p.3351-3362
Abstract
Proteoglycans (PGs) are macromolecules that consist of long linear polysaccharides, glycosaminoglycan (GAG) chains, covalently attached to a core protein by the carbohydrate xylose. The biosynthesis of GAG chains is initiated by xylosylation of the core protein followed by galactosylation by the galactosyltransferase β4GalT7. Some β-d-xylosides, such as 2-naphthyl β-d-xylopyranoside, can induce GAG synthesis by serving as acceptor substrates for β4GalT7 and by that also compete with the GAG synthesis on core proteins. Here we present structure-activity relationships for β4GalT7 and xylosides with modifications of the aromatic aglycon, using enzymatic assays, cell studies, and molecular docking simulations. The results show that the... (More)
Proteoglycans (PGs) are macromolecules that consist of long linear polysaccharides, glycosaminoglycan (GAG) chains, covalently attached to a core protein by the carbohydrate xylose. The biosynthesis of GAG chains is initiated by xylosylation of the core protein followed by galactosylation by the galactosyltransferase β4GalT7. Some β-d-xylosides, such as 2-naphthyl β-d-xylopyranoside, can induce GAG synthesis by serving as acceptor substrates for β4GalT7 and by that also compete with the GAG synthesis on core proteins. Here we present structure-activity relationships for β4GalT7 and xylosides with modifications of the aromatic aglycon, using enzymatic assays, cell studies, and molecular docking simulations. The results show that the aglycons reside on the outside of the active site of the enzyme and that quite bulky aglycons are accepted. By separating the aromatic aglycon from the xylose moiety by linkers, a trend towards increased galactosylation with increased linker length is observed. The galactosylation is influenced by the identity and position of substituents in the aromatic framework, and generally, only xylosides with β-glycosidic linkages function as good substrates for β4GalT7. We also show that the galactosylation ability of a xyloside is increased by replacing the anomeric oxygen with sulfur, but decreased by replacing it with carbon. Finally, we propose that reaction kinetics of galactosylation by β4GalT7 is dependent on subtle differences in orientation of the xylose moiety. (Less)
Please use this url to cite or link to this publication:
author
, et al. (More)
(Less)
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Organic and Biomolecular Chemistry
volume
13
issue
11
pages
3351 - 3362
publisher
Royal Society of Chemistry
external identifiers
  • pmid:25655827
  • wos:000351062700025
  • scopus:84924308982
ISSN
1477-0539
DOI
10.1039/c4ob02632b
language
English
LU publication?
yes
id
fbf673db-434a-4b4f-a4c0-1598e08f1545 (old id 5145336)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/25655827?dopt=Abstract
date added to LUP
2015-03-04 18:33:12
date last changed
2017-11-05 03:11:18
@article{fbf673db-434a-4b4f-a4c0-1598e08f1545,
  abstract     = {Proteoglycans (PGs) are macromolecules that consist of long linear polysaccharides, glycosaminoglycan (GAG) chains, covalently attached to a core protein by the carbohydrate xylose. The biosynthesis of GAG chains is initiated by xylosylation of the core protein followed by galactosylation by the galactosyltransferase β4GalT7. Some β-d-xylosides, such as 2-naphthyl β-d-xylopyranoside, can induce GAG synthesis by serving as acceptor substrates for β4GalT7 and by that also compete with the GAG synthesis on core proteins. Here we present structure-activity relationships for β4GalT7 and xylosides with modifications of the aromatic aglycon, using enzymatic assays, cell studies, and molecular docking simulations. The results show that the aglycons reside on the outside of the active site of the enzyme and that quite bulky aglycons are accepted. By separating the aromatic aglycon from the xylose moiety by linkers, a trend towards increased galactosylation with increased linker length is observed. The galactosylation is influenced by the identity and position of substituents in the aromatic framework, and generally, only xylosides with β-glycosidic linkages function as good substrates for β4GalT7. We also show that the galactosylation ability of a xyloside is increased by replacing the anomeric oxygen with sulfur, but decreased by replacing it with carbon. Finally, we propose that reaction kinetics of galactosylation by β4GalT7 is dependent on subtle differences in orientation of the xylose moiety.},
  author       = {Siegbahn, Anna and Thorsheim, Karin and Ståhle, Jonas and Manner, Sophie and Hamark, Christoffer and Persson, Andrea and Tykesson, Emil and Mani, Katrin and Westergren-Thorsson, Gunilla and Widmalm, Göran and Ellervik, Ulf},
  issn         = {1477-0539},
  language     = {eng},
  number       = {11},
  pages        = {3351--3362},
  publisher    = {Royal Society of Chemistry},
  series       = {Organic and Biomolecular Chemistry},
  title        = {Exploration of the active site of β4GalT7: modifications of the aglycon of aromatic xylosides.},
  url          = {http://dx.doi.org/10.1039/c4ob02632b},
  volume       = {13},
  year         = {2015},
}