scholarly journals Structure of the heparan sulfate-protein linkage region. Demonstration of the sequence galactosyl-galactosyl-xylose-2-phosphate.

1985 ◽  
Vol 260 (27) ◽  
pp. 14722-14726 ◽  
Author(s):  
L A Fransson ◽  
I Silverberg ◽  
I Carlstedt
Keyword(s):  
Heparan Sulfate ◽  
Linkage Region

scholarly journals Location ofN-Unsubstituted Glucosamine Residues in Heparan Sulfate

2002 ◽  
Vol 277 (51) ◽  
pp. 49247-49255 ◽  
Author(s):  
Camilla Westling ◽  
Ulf Lindahl
Keyword(s):  
Heparan Sulfate ◽  
Functional Properties ◽  
Structural Characterization ◽  
Nitrous Acid ◽  
Human Aorta ◽  
Linkage Region ◽  
Hexuronic Acid ◽  
Functional Implications ◽  
Sulfation Pattern

Functional properties of heparan sulfate (HS) are generally ascribed to the sulfation pattern of the polysaccharide. However, recently reported functional implications of rareN-unsubstituted glucosamine (GlcNH2) residues in native HS prompted our structural characterization of sequences around such residues. HS preparations were cleaved with nitrous acid at eitherN-sulfated orN-unsubstituted glucosamine units followed by reduction with NaB3H4. The labeled products were characterized following complementary deamination steps. The proportion of GlcNH2units varied from 0.7–4% of total glucosamine in different HS preparations. The GlcNH2units occurred largely clustered at the polysaccharide-protein linkage region in intestinal HS, also more peripherally in aortic HS. They were preferentially located withinN-acetylated domains, or in transition sequences betweenN-acetylated andN-sulfated domains, only 20–30% of the adjacent upstream and downstream disaccharide units beingN-sulfated. The nearest downstream (toward the polysaccharide-protein linkage) hexuronic acid was invariably GlcUA, whereas the upstream neighbor could be either GlcUA or IdoUA. The highly sulfated butN-unsubstituted disaccharide unit, -IdoUA2S-GlcNH26S-, was detected in human renal and porcine intestinal HS, but not in HS from human aorta. These results are interpreted in terms of a biosynthetic mechanism, whereby GlcNH2residues are formed through regulated, incomplete action of anN-deacetylase/N-sulfotransferase enzyme.

scholarly journals Human Xylosyltransferase II Is Involved in the Biosynthesis of the Uniform Tetrasaccharide Linkage Region in Chondroitin Sulfate and Heparan Sulfate Proteoglycans

2006 ◽  
Vol 282 (8) ◽  
pp. 5201-5206 ◽  
Author(s):  
Claudia Pönighaus ◽  
Michael Ambrosius ◽  
Javier Carrera Casanova ◽  
Christian Prante ◽  
Joachim Kuhn ◽  
...  
Keyword(s):  
Heparan Sulfate ◽  
Chondroitin Sulfate ◽  
Heparan Sulfate Proteoglycans ◽  
Linkage Region

FAM20B is a kinase that phosphorylates xylose in the glycosaminoglycan–protein linkage region

2009 ◽  
Vol 421 (2) ◽  
pp. 157-162 ◽  
Author(s):  
Toshiyasu Koike ◽  
Tomomi Izumikawa ◽  
Jun-Ichi Tamura ◽  
Hiroshi Kitagawa
Keyword(s):  
Rna Interference ◽  
Heparan Sulfate ◽  
Chondroitin Sulfate ◽  
Hela Cells ◽  
Unknown Function ◽  
Gel Filtration ◽  
Transfected Cells ◽  
Linkage Region ◽  
Xylose Residue ◽  
Weak Similarity

2-O-phosphorylation of xylose has been detected in the glycosaminoglycan–protein linkage region, GlcAβ1-3Galβ1-3Galβ1-4Xylβ1-O-Ser, of proteoglycans. Recent mutant analyses in zebrafish suggest that xylosyltransferase I and FAM20B, a protein of unknown function that shows weak similarity to a Golgi kinase encoded by four-jointed, operate in a linear pathway for proteoglycan production. In the present study, we identified FAM20B as a kinase that phosphorylates the xylose residue in the linkage region. Overexpression of FAM20B increased the amount of both chondroitin sulfate and heparan sulfate in HeLa cells, whereas the RNA interference of FAM20B resulted in a reduction of their amount in the cells. Gel-filtration analysis of the glycosaminoglycan chains synthesized in the overexpressing cells revealed that the glycosaminoglycan chains had a similar length to those in mock-transfected cells. These results suggest that FAM20B regulates the number of glycosaminoglycan chains by phosphorylating the xylose residue in the glycosaminoglycan–protein linkage region of proteoglycans.

Biosynthesis of heparan sulfate in EXT1-deficient cells

2010 ◽  
Vol 428 (3) ◽  
pp. 463-471 ◽  
Author(s):  
Megumi Okada ◽  
Satomi Nadanaka ◽  
Naoko Shoji ◽  
Jun-ichi Tamura ◽  
Hiroshi Kitagawa
Keyword(s):  
Heparan Sulfate ◽  
Genetic Disorder ◽  
Transferase Activity ◽  
Hereditary Multiple Exostoses ◽  
Targeted Deletion ◽  
Biologically Relevant ◽  
Glcnac Residue ◽  
Linkage Region ◽  
Distinct Cell ◽  
Multiple Exostoses

HS (heparan sulfate) is synthesized by HS co-polymerases encoded by the EXT1 and EXT2 genes (exostosin 1 and 2), which are known as causative genes for hereditary multiple exostoses, a dominantly inherited genetic disorder characterized by multiple cartilaginous tumours. It has been thought that the hetero-oligomeric EXT1–EXT2 complex is the biologically relevant form of the polymerase and that targeted deletion of either EXT1 or EXT2 leads to a complete lack of HS synthesis. In the present paper we show, unexpectedly, that two distinct cell lines defective in EXT1 expression indeed produce small but significant amounts of HS chains. The HS chains produced without the aid of EXT1 were shorter than HS chains formed in concert with EXT1 and EXT2. In addition, biosynthesis of HS in EXT1-defective cells was notably blocked by knockdown of either EXT2 or EXTL2 (EXT-like), but not of EXTL3. Then, to examine the roles of EXTL2 in the biosynthesis of HS in EXT1-deficient cells, we focused on the GlcNAc (N-aetylglucosamine) transferase activity of EXTL2, which is involved in the initiation of HS chains by transferring the first GlcNAc to the linkage region. Although EXT2 alone synthesized no heparan polymers on the synthetic linkage region analogue GlcUAβ1-3Galβ1-O-C2H4NH-benzyloxycarbonyl, marked polymerization by EXT2 alone was demonstrated on GlcNAcα1-4GlcUAβ1-3Galβ1-O-C2H4N-benzyloxycarbonyl (where GlcUA is glucuronic acid and Gal is galactose), which was generated by transferring a GlcNAc residue using recombinant EXTL2 on to GlcUAβ1–3Galβ1-O-C2H4NH-benzyloxycarbonyl. These findings indicate that the transfer of the first GlcNAc residue to the linkage region by EXTL2 is critically required for the biosynthesis of HS in cells deficient in EXT1.

Localization of cell-surface and basement-membrane heparan-sulfate proteoglycans using the malaria circumsporozoite protein

1994 ◽  
Vol 52 ◽  
pp. 294-295
Author(s):  
U. Frevert ◽  
S. Sinnis ◽  
C. Cerami ◽  
V. Nussenzweig
Keyword(s):  
Heparan Sulfate ◽  
Protein A ◽  
Kidney Tissue ◽  
Plasmodium Species ◽  
Its Region ◽  
Basement Membranes ◽  
Heparan Sulfate Proteoglycans ◽  
Infected Mosquito ◽  
Complement Components ◽  
Region Ii

Malaria sporozoites, which invade hepatocytes within minutes after transmission by an infected mosquito, are covered with the circumsporozoite (CS) protein, which in all Plasmodium species contains the conserved region II-plus. This region is also found as a cell-adhesive motif in a variety of host proteins like thrombospondin, properdin and the terminal complement components.The CS protein with its region II-plus specifically binds to heparan sulfate proteoglycans (HSPG) on the basolateral surface of hepatocytes in the space of Disse (FIG. 1), to certain basolateral cell membranes and basement membranes of the kidney (FIG. 2) as well as to heparin in the granules of connective tissue mast cells. The distribution of the HSPG receptors for the CS protein was examined by incubation of Lowicryl K4M or LR White sections of liver and kidney tissue with the recombinant CS ligand, whose binding sites were detected with a monoclonal anti-CS antibody and protein A gold.

Specific Cross-reaction of IgG Anti-phospholipid Antibody with Platelet Glycoprotein IIIa

1996 ◽  
Vol 75 (01) ◽  
pp. 168-174 ◽  
Author(s):  
Shigeru Tokita ◽  
Morio Arai ◽  
Naomasa Yamamoto ◽  
Yasuhiro Katagiri ◽  
Kenjiro Tanoue ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Heparan Sulfate ◽  
Disulfide Bonds ◽  
Dextran Sulfate ◽  
Human Platelets ◽  
Platelet Glycoprotein ◽  
Activated Platelets ◽  
Fibrinogen Binding ◽  
Dose Dependent Fashion ◽  
Glycoprotein Iiia

SummaryTo study the pathological functions of anti-phospholipid (anti-PL) antibodies, we have analyzed their effect on platelet function. We identified an IgG anti-PL mAb, designated PSG3, which cross-reacted specifically with glycoprotein (GP) IIIa in human platelets and inhibited platelet aggregation. PSG3 bound also to certain polyanionic substances, such as double-stranded DNA, heparan sulfate, dextran sulfate and acetylated-LDL, but not to other polyanionic substances. The binding of PSG3 to GPIIIa was completely inhibited by heparan sulfate and dextran sulfate, indicating that PSG3 recognizes a particular array of negative charges expressed on both GPIIIa and the specified polyanionic substances. Since neither neuraminidase- nor endoglycopeptidase F-treatment of GPIIIa had any significant effect on the binding of PSG3, this array must be located within the amino acid sequence of GPIIIa but not in the carbohydrate moiety. Reduction of the disulfide bonds in GPIIIa greatly reduced its reactivity, suggesting that the negative charges in the epitope are arranged in a particular conformation. PSG3 inhibited platelet aggregation induced by either ADP or collagen, it also inhibited fibrinogen binding to activated platelets in a dose-dependent fashion. PSG3, however, did not inhibit the binding of GRGDSP peptide to activated platelets. These results suggest that the PSG3 epitope on GPIIIa contains a particular array of negative charges, and possibly affects the fibrinogen binding to GPIIb/IIIa complex necessary for platelet aggregation.

Sign in / Sign up

Export Citation Format

Share Document