Structural Analysis of Heparin-Derived 3- O -Sulfated Tetrasaccharides: Antithrombin Binding Site Variants

Abstract

Heparin is a polysaccharide that is widely used as an anticoagulant drug. The mechanism for heparin’s anticoagulant activity is primarily through its interaction with a serine protease inhibitor, antithrombin III (AT), that enhances its ability to inactivate blood coagulation serine proteases, including thrombin (factor IIa) and factor Xa. The AT-binding site in the heparin is one of the most well-studied carbohydrate-protein binding sites and its structure is the basis for the synthesis of the heparin pentasaccharide drug, fondaparinux. Despite our understanding of the structural requirements for the heparin pentasaccharide AT-binding site, there is a lack of data on the natural variability of these binding sites in heparins extracted from animal tissues. The present work provides a detailed study on the structural variants of the tetrasaccharide fragments of this binding site afforded following treatment of a heparin with heparin lyase II. The 5 most commonly observed tetrasaccharide fragments of the AT-binding site are fully characterized, and a method for their quantification in heparin and low-molecular-weight heparin products is described.

Structure and Neuroprotective Effect of Polysaccharide from Viscera Autolysates of Squid Ommastrephes bartrami

“…Besides the anomeric signals, the other ring proton signals were at the region of 3.4–4.4. In addition, the 1 H NMR spectrum showed two methyl groups at 1.19 and 1.98 ppm, which represented the C6 methyl group of fucose and CH 3 of acetyl group respectively [14,15].…”

“…1 H NMR, HSQC NMR, 1 H– 1 H COSY and TOCSY were performed on a Bruker 800-MHz NMR spectrometer and acquisition of the spectra was carried out using Topspin 2.1.6 software. All spectra were acquired at a temperature of 298 K [14].…”

Chemoenzymatic synthesis of heparan sulfate and heparin oligosaccharides and NMR analysis: paving the way to a diverse library for glycobiologists

“… 5 A pentasaccharide sequence motif present within HS and heparin polysaccharides including, →4)GlcNS6S(1→4)GlcA(1→4)GlcNS3S6S(1→4)IdoA2S(1→4)GlcNS6S(1→, is responsible for its specific binding to the serine protease inhibitor (serpin) antithrombin III (AT). 6 A repeating trisulfated disaccharide sequence →4)IdoA2S(1→4)GlcNS6S(1→ corresponds to heparin's thrombin (or factor IIa, FIIa) binding site and facilitates the assembly of the ternary heparin–AT–FIIa complex required for heparin's global anticoagulant activity. 7…”

Analysis of thrombin‐antithrombin complex formation using microchip electrophoresis and mass spectrometry

“…TAT is formed using thrombin (T) and antithrombin (AT) proteins; this reaction typically occurs in the presence of a carbohydrate catalyst, heparin (Hep) . The complex is made by complexing AT with Hep, followed by the addition of T as shown in Fig.…”