Signal amplification of target protein on heparin glycan microarray

Abstract

A heparin glycan chip (HepGlyChip) with 4800-fold enhanced signal-to-noise ratio as compared to the control without heparin was developed for high-throughput analysis of heparin-protein interactions for new drug development and for the screening biological samples in diagnostic applications. As a proof of concept, a heparin glycan microarray was prepared on a poly (styreneco-maleic anhydride) (PS-MA)-coated glass slide. Heparin was covalently immobilized on poly-Llysine (PLL) layer with multiple binding sites by sulfo-ethylene glycol bis(succinimidylsuccinate) (sulfo-EGS), increasing the signal to noise ratio, minimizing non-specific binding of target proteins, and resulting in a 3-dimensional (3D) structure on the HepGlyChip. This on-chip signal amplification platform was successfully demonstrated by probing the heparin microarray with the highly specific heparin-binding protein, antithrombin III (AT III).

Glycan microarrays of fluorescently-tagged natural glycans

“…Although natural GAG oligomers have been used for glycan microarray analysis, there is no systematic study of this topic [60,61]. The challenge lies presumably in the high heterogeneity of the sulfation patterns of the GAG chains, making the large scale separation of GAG glycans an intimidating task.…”

Engineering of routes to heparin and related polysaccharides

“…Protected glucosamine and glucuronic acid building blocks with azide and alkyne functional groups allow for the rapid and efficient iterative 1,3-dipolar cycloaddition leading to formation of β(1–4) linkage as heparosan analogs. Microarrays for screening protein binding to synthetic heparin oligosaccharides or polysaccharides attached to a chip through an amine linker, compatible with protection group chemistry, have led to high throughput screening (de Paz et al 2006; Park et al 2008). Development of such combinatorial oligosaccharide libraries based on chemical synthesis provides for a powerful tool in SAR studies (Figure 2) for heparin and HS through the use of such high throughput microarrays.…”

Biocompatible charcoal composites prepared by ionic liquids for drug detoxification

“…13 Clinically, there is a strong need to develop biocompatible charcoal composites capable of prohibiting clot formation and thrombosis during hemoperfusion, kidney dialysis, and preparation of vascular grafts. [13][14][15][16][17] To improve the biocompatibility of activated charcoal, we tried to coat active charcoal with cellulose and heparin using ionic liquids (ILs). ILs are organic liquids that are useful in overcoming the lack of solubility of many nonpolar and polar compounds, including carbohydrates, when these are required to be designed and synthesized in conventional organic solvents.…”