Dermatan is a better substrate for 4-O-sulfation than chondroitin : implications in the generation of 4-O-sulfated, L-iduronate-rich galactosaminoglycans
Eklund, Erik LU ; Rodén, Lennart ; Malmström, Marianne LU and Malmström, A LU
(2000)
In Archives of Biochemistry and Biophysics
383(2).
p.171-177
- Abstract
The biosynthesis of dermatan sulfate is a complex process that involves, inter alia, formation of L-iduronic acid residues by C5-epimerization of D-glucuronic acid residues already incorporated into the growing polymer. It has been shown previously that this reaction is promoted by the presence of the sulfate donor 3'-phosphoadenosine-5'-phosphosulfate. In the present investigation, the role of sulfation in the biosynthesis of L-iduronic acid-rich galactosaminoglycans was examined more closely by a study of the substrate specificities and kinetic properties of the sulfotransferases involved in dermatan sulfate biosynthesis. Comparison of the acceptor reactivities of oligosaccharides from chondroitin and dermatan, in an in vitro system... (More)
The biosynthesis of dermatan sulfate is a complex process that involves, inter alia, formation of L-iduronic acid residues by C5-epimerization of D-glucuronic acid residues already incorporated into the growing polymer. It has been shown previously that this reaction is promoted by the presence of the sulfate donor 3'-phosphoadenosine-5'-phosphosulfate. In the present investigation, the role of sulfation in the biosynthesis of L-iduronic acid-rich galactosaminoglycans was examined more closely by a study of the substrate specificities and kinetic properties of the sulfotransferases involved in dermatan sulfate biosynthesis. Comparison of the acceptor reactivities of oligosaccharides from chondroitin and dermatan, in an in vitro system containing microsomes from cultured human skin fibroblasts and 3'-phosphoadenosine-5'-phosphosulfate, showed that Km values for the dermatan fragments were substantially lower than those for their chondroitin counterparts. Calculation of Vmax values likewise showed that dermatan was the better substrate. Whereas dermatan incorporated [35S]sulfate exclusively at the C4 position of N-acetylgalactosamine residues, approximately equal amounts of radioactivity were found at the C4 and C6 positions in the labelled chondroitin. Under standard assay conditions, the 4-O-sulfation of dermatan proceeded about six times faster than the 4-O-sulfation of chondroitin. On the basis of these results, we propose that L-iduronic acids, formed in the course of the biosynthesis of dermatan sulfates, enhance sulfation of their adjacent N-acetylgalactosamine residues, and will thereby be locked in the L-ido configuration.
(Less)
- author
- Eklund, Erik
LU
; Rodén, Lennart
; Malmström, Marianne
LU
and Malmström, A
LU
- organization
- publishing date
- 2000
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Cells, Cultured, Chondroitin/chemistry, Chromatography, Affinity, Dermatan Sulfate/chemistry, Dose-Response Relationship, Drug, Fibroblasts/chemistry, Galactosamine/biosynthesis, Hexuronic Acids/pharmacology, Humans, Hydrogen-Ion Concentration, Iduronic Acid/chemistry, Kinetics, Phosphoadenosine Phosphosulfate/metabolism, Protein Binding, Substrate Specificity, Sulfotransferases/chemistry, Time Factors
- in
- Archives of Biochemistry and Biophysics
- volume
- 383
- issue
- 2
- pages
- 171 - 177
- publisher
- Academic Press
- external identifiers
-
- scopus:0034669716
- pmid:11185550
- ISSN
- 0003-9861
- DOI
- 10.1006/abbi.2000.2043
- language
- English
- LU publication?
- yes
- id
- ef58a115-e1d6-48cd-b598-88926a1a9ef8
- date added to LUP
- 2021-10-12 00:10:36
- date last changed
- 2024-01-05 17:50:48
@article{ef58a115-e1d6-48cd-b598-88926a1a9ef8,
abstract = {{<p>The biosynthesis of dermatan sulfate is a complex process that involves, inter alia, formation of L-iduronic acid residues by C5-epimerization of D-glucuronic acid residues already incorporated into the growing polymer. It has been shown previously that this reaction is promoted by the presence of the sulfate donor 3'-phosphoadenosine-5'-phosphosulfate. In the present investigation, the role of sulfation in the biosynthesis of L-iduronic acid-rich galactosaminoglycans was examined more closely by a study of the substrate specificities and kinetic properties of the sulfotransferases involved in dermatan sulfate biosynthesis. Comparison of the acceptor reactivities of oligosaccharides from chondroitin and dermatan, in an in vitro system containing microsomes from cultured human skin fibroblasts and 3'-phosphoadenosine-5'-phosphosulfate, showed that Km values for the dermatan fragments were substantially lower than those for their chondroitin counterparts. Calculation of Vmax values likewise showed that dermatan was the better substrate. Whereas dermatan incorporated [35S]sulfate exclusively at the C4 position of N-acetylgalactosamine residues, approximately equal amounts of radioactivity were found at the C4 and C6 positions in the labelled chondroitin. Under standard assay conditions, the 4-O-sulfation of dermatan proceeded about six times faster than the 4-O-sulfation of chondroitin. On the basis of these results, we propose that L-iduronic acids, formed in the course of the biosynthesis of dermatan sulfates, enhance sulfation of their adjacent N-acetylgalactosamine residues, and will thereby be locked in the L-ido configuration.</p>}},
author = {{Eklund, Erik and Rodén, Lennart and Malmström, Marianne and Malmström, A}},
issn = {{0003-9861}},
keywords = {{Cells, Cultured; Chondroitin/chemistry; Chromatography, Affinity; Dermatan Sulfate/chemistry; Dose-Response Relationship, Drug; Fibroblasts/chemistry; Galactosamine/biosynthesis; Hexuronic Acids/pharmacology; Humans; Hydrogen-Ion Concentration; Iduronic Acid/chemistry; Kinetics; Phosphoadenosine Phosphosulfate/metabolism; Protein Binding; Substrate Specificity; Sulfotransferases/chemistry; Time Factors}},
language = {{eng}},
number = {{2}},
pages = {{171--177}},
publisher = {{Academic Press}},
series = {{Archives of Biochemistry and Biophysics}},
title = {{Dermatan is a better substrate for 4-O-sulfation than chondroitin : implications in the generation of 4-O-sulfated, L-iduronate-rich galactosaminoglycans}},
url = {{http://dx.doi.org/10.1006/abbi.2000.2043}},
doi = {{10.1006/abbi.2000.2043}},
volume = {{383}},
year = {{2000}},
}