High-affinity heparins

It is obtained as fragments of commercial grade heparin which is produced by chemical or enzymatic depolymerisation. It contains less pentasaccharide sequences with a high affinity for antithrombin III. 

The results were explained by two effects (1) dehydration of cations and guanine 06 atomic group and (2) the water uptake upon folding of a single-stranded DNA into a G-quadruplex [29]. It is, however, interesting that DNA aptamer with high affinity to heparin binding site is insensitive to K+ ions [17]. 

Use, for example, 32-mer DNA aptamer modified by biotin at 3 end of the following sequence 3 -BIO-GGG TTT TCA CTT TTG TGG GTT GGA CGG GAT GG - 5. This aptamer has at its 5 end typical motif with high affinity to the heparin-binding site of the thrombin [1], (Please note that aptamer that selectively bind the fibrinogen-binding site of thrombin has a different structure—see Chapter 33 in CD accompanying this book). The aptamer can be purchased from Thermo Electron Corporation, Germany. 

Robinson MJ, Tessier P, Poulsom R, Hogg N. 2002. The S100 family heterodimer, MRP-8/14, binds with high affinity to heparin and heparan sulfate glycosaminoglycans on endothelial cells. J Biol Chem 277(5) 3658—3665. 

W12. Weisgraber, K. H., and Mahley, R. W., Subfractionation of human high density lipoproteins by heparin-Sepharose affinity chromatography. /. Lipid Res. 21, 316-325 (1980). 

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