A Highly Stable Covalent Conjugated Heparin Biochip for Heparin–Protein Interaction Studies
✍ Scribed by Fuming Zhang; Melissa Fath; Rory Marks; Robert J. Linhardt
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 47 KB
- Volume
- 304
- Category
- Article
- ISSN
- 0003-2697
No coin nor oath required. For personal study only.
✦ Synopsis
Heparin is a proteoglycan composed of highly sulfated linear polysaccharides of alternating uronic acid and glucosamine that interacts with a wide variety of proteins and peptides (1). Heparin and the structurally related heparan sulfate are the most acidic polysaccarides in the human body and, as a result, interact with many cationic proteins, giving rise to myriad biological activities (2). Some of these interactions have received extensive attention in recent years, including heparin's binding to growth factors (3, 4) influencing angiogenesis and other proliferation-dependent processes, and its binding to the ectodomain proteins of pathogens influencing infection (5).
Surface plasmon resonance (SPR) 2 spectroscopy has become one of several established methods for measuring biomolecular interactions (6). SPR measures binding interactions on the surface of a biosensor chip, and SPR biosensors have been successfully used for quantitative modeling of heparin-protein interactions (3, 7-9). These experiments require the immobilization of either heparin or the heparin-binding protein on the surface of a biosensor chip, over which its binding partner (heparin-binding protein or heparin) is passed. While a number of immobilization chemistries have been developed to immobilize proteins for SPR (6), this may be problematic as proteins differ with respect to ease of covalent attachment to a surface with retention of native conformation, accessibility of active sites, and bioactivity. In natural biological systems, heparan sulfate is found immobilized on the cell surface through its core protein (10), and captures heparin-binding proteins that flow over the cell surface. Modeling this interaction by SPR would best be achieved by immobilizing heparin/heparan sulfate rather than the heparin-binding protein. However, the presence of only a