Synthesis of Tri-And Tetrasaccharides Present in the Linkage Region of Heparin and Heparan Sulphate

The distribution of N-sulphate groups within fibroblast heparan sulphate chains was investigated. The detergent-extractable heparan sulphate proteoglycan from adult human skin fibroblasts, radiolabelled with [3H]glucosamine and [35S]sulphate, was coupled to CNBr-activated Sepharose 4B. After partial depolymerization of the heparan sulphate with nitrous acid, the remaining Sepharose-bound fragments were removed by treatment with alkali. These fragments, of various sizes, but all containing an intact reducing xylose residue, were fractionated on Sephacryl S-300 and the distribution of the 3H and 35S radiolabels was analysed. A decreased degree of sulphation was observed towards the reducing termini of the chains. After complete nitrous acid hydrolysis of the Sepharose-bound proteoglycan, analysis of the proximity of N-sulphation to the reducing end revealed the existence of an extended N-acetylated sequence directly adjacent to the protein-linkage sequence. The size of this N-acetylated domain was estimated by gel filtration to be approximately eight disaccharide units. This domain appears to be highly conserved, being present in virtually all the chains derived from this proteoglycan, implying the existence of a mechanism capable of generating such a non-random sequence during the post-polymeric modification of heparan sulphate. Comparison with the corresponding situation in heparin suggests that different mechanisms regulate polymer N-sulphation in the vicinity of the protein-linkage region of these chemically related glycosaminoglycans.

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New insights into heparan sulphate biosynthesis from the study of mutant mice

Biochemical Society Symposium ◽

10.1042/bss0690047 ◽

2002 ◽

Vol 69 ◽

pp. 47-57 ◽

Cited By ~ 8

Author(s):

Catherine L. R. Merry ◽

John T. Gallagher

Keyword(s):

Growth Factors ◽

Biosynthetic Pathway ◽

Heparan Sulphate ◽

Mutant Mice ◽

Gene Products ◽

Multiple Gene ◽

Adhesion Proteins ◽

Ligand Interactions

Heparan sulphate (HS) is an essential co-receptor for a number of growth factors, morphogens and adhesion proteins. The biosynthetic modifications involved in the generation of a mature HS chain may determine the strength and outcome of HS–ligand interactions. These modifications are catalysed by a complex family of enzymes, some of which occur as multiple gene products. Various mutant mice have now been generated, which lack the function of isolated components of the HS biosynthetic pathway. In this discussion, we outline the key findings of these studies, and use them to put into context our own work concerning the structure of the HS generated by the Hs2st-/- mice.

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Neutralisation of Heparan Sulphate and Low Molecular Weight Heparin by Protamine

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661242 ◽

1985 ◽

Vol 53 (01) ◽

pp. 086-089 ◽

Cited By ~ 22

Author(s):

A R Hubbard ◽

C A Jennings

Keyword(s):

Molecular Weight ◽

Plasma Proteins ◽

Low Molecular Weight Heparin ◽

Heparan Sulphate ◽

Activated Partial Thromboplastin Time ◽

Weight Basis ◽

Low Molecular Weight ◽

Protamine Sulphate ◽

At Iii ◽

Reference Preparation

SummaryThe neutralisation by protamine sulphate (PS) of heparan sulphate (HS), a low molecular weight heparin (LMWH), and a reference preparation of unfractionated heparin (UH), was studied by activated partial thromboplastin time (APTT) and anti-Xa clotting assays. UH was most easily neutralised in the APTT assay by PS (on a weight for weight basis), followed by LMWH and HS. The neutralisation of APTT activity by PS closely followed the loss of activity in the anti-Xa clotting assay, when plasma was used as the source of At III. When the anti-Xa clotting assay was carried out using purified At III in place of plasma, HS and LMWH were neutralised by much lower amounts of PS and resembled UH neutralisation more closely. Resistance of HS anti-Xa activity to PS neutralisation decreased with increasing plasma dilution. The presence of bovine albumin with purified At III concentrate increased the resistance of HS to PS neutralisation. It is concluded that PS binding to UH, HS and LMWH is probably related more to their degree of sulphation than molecular weight and that non-specific interactions between PS and plasma proteins inhibit the binding of PS to HS and LMWH.

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Faculty Opinions recommendation of Fell-Muir Lecture: Heparan sulphate and the art of cell regulation: a polymer chain conducts the protein orchestra.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.725855956.793510483 ◽

2015 ◽

Author(s):

John R Couchman

Keyword(s):

Polymer Chain ◽

Heparan Sulphate ◽

Cell Regulation

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What Are the Potential Roles of Nuclear Perlecan and Other Heparan Sulphate Proteoglycans in the Normal and Malignant Phenotype

International Journal of Molecular Sciences ◽

10.3390/ijms22094415 ◽

2021 ◽

Vol 22 (9) ◽

pp. 4415

Author(s):

Anthony J. Hayes ◽

James Melrose

Keyword(s):

Gene Expression ◽

Nuclear Envelope ◽

Annulus Fibrosus ◽

Heparan Sulphate ◽

Cell Types ◽

Malignant Cell ◽

Cytoskeletal Proteins ◽

Nucleus Pulposus Cells ◽

Malignant Phenotype ◽

Heparan Sulphate Proteoglycans

The recent discovery of nuclear and perinuclear perlecan in annulus fibrosus and nucleus pulposus cells and its known matrix stabilizing properties in tissues introduces the possibility that perlecan may also have intracellular stabilizing or regulatory roles through interactions with nuclear envelope or cytoskeletal proteins or roles in nucleosomal-chromatin organization that may regulate transcriptional factors and modulate gene expression. The nucleus is a mechano-sensor organelle, and sophisticated dynamic mechanoresponsive cytoskeletal and nuclear envelope components support and protect the nucleus, allowing it to perceive and respond to mechano-stimulation. This review speculates on the potential roles of perlecan in the nucleus based on what is already known about nuclear heparan sulphate proteoglycans. Perlecan is frequently found in the nuclei of tumour cells; however, its specific role in these diseased tissues is largely unknown. The aim of this review is to highlight probable roles for this intriguing interactive regulatory proteoglycan in the nucleus of normal and malignant cell types.

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The Endothelial Glycocalyx as a Target of Ischemia and Reperfusion Injury in Kidney Transplantation—Where Have We Gone So Far?

International Journal of Molecular Sciences ◽

10.3390/ijms22042157 ◽

2021 ◽

Vol 22 (4) ◽

pp. 2157

Author(s):

Anila Duni ◽

Vassilios Liakopoulos ◽

Vasileios Koutlas ◽

Charalampos Pappas ◽

Michalis Mitsis ◽

...

Keyword(s):

Kidney Transplantation ◽

Reperfusion Injury ◽

Heparan Sulphate ◽

Graft Function ◽

Endothelial Permeability ◽

Endothelial Glycocalyx ◽

Ischemia And Reperfusion Injury ◽

New Era ◽

Sphingosine 1 Phosphate

The damage of the endothelial glycocalyx as a consequence of ischemia and/or reperfusion injury (IRI) following kidney transplantation has come at the spotlight of research due to potential associations with delayed graft function, acute rejection as well as long-term allograft dysfunction. The disintegration of the endothelial glycocalyx induced by IRI is the crucial event which exposes the denuded endothelial cells to further inflammatory and oxidative damage. The aim of our review is to present the currently available data regarding complex links between shedding of the glycocalyx components, like syndecan-1, hyaluronan, heparan sulphate, and CD44 with the activation of intricate immune system responses, including toll-like receptors, cytokines and pro-inflammatory transcription factors. Evidence on modes of protection of the endothelial glycocalyx and subsequently maintenance of endothelial permeability as well as novel nephroprotective molecules such as sphingosine-1 phosphate (S1P), are also depicted. Although advances in technology are making the visualization and the analysis of the endothelial glycocalyx possible, currently available evidence is mostly experimental. Ongoing progress in understanding the complex impact of IRI on the endothelial glycocalyx, opens up a new era of research in the field of organ transplantation and clinical studies are of utmost importance for the future.

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