Kinetic and structural studies on interactions between heparin or heparan sulfate and proteins of the hedgehog signaling pathway.
Heparan sulfate (HS) proteoglycans (PGs) interact with a number of extracellular signaling proteins, thereby playing an essential role in the regulation of many physiological processes. These interactions are important for both normal signal transduction and regulation of the tissue distribution of signaling molecules. In this study, we use surface plasmon resonance (SPR) to study interactions of HS and structurally related heparin with proteins in the Hedgehog signaling pathway. SPR analysis shows that heparin binds with different affinities to active fragments of the proteins Hedgehog (Hh), Interference Hedgehog (Ihog), Cam-related/Down-regulated by Oncogenes (CDO), and Sonic Hedgehog (Shh). Solution competition studies show that the minimum size of a heparin oligosaccharide capable of interacting with Ihog is larger than a tetrasaccharide and for interacting with Shh is larger than an octasaccharide. In comparison with heparin, Ihog and Shh exhibited a lower affinity for HS than for heparin, and CDO and Hh exhibit negligible binding to HS. This study clearly demonstrates Shh and Ihog are heparin and HS binding proteins and that both molecules preferentially bind heparin or HS having a high level of sulfation.
Zhang
Fuming
F
Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, USA. zhangf2@rpi.edu
McLellan
Jason S
JS
Ayala
Alondra M
AM
Leahy
Daniel J
DJ
Linhardt
Robert J
RJ
D000818:Animals; D015815:Cell Adhesion Molecules / Q000737:chemistry; D029721:Drosophila Proteins / Q000737:chemistry*; D053823:Hedgehog Proteins / Q000737:chemistry / Q000502:physiology*; D006493:Heparin / Q000737:chemistry*; D006497:Heparan Sulfate / Q000737:chemistry*; D007700:Kinetics; D008562:Membrane Glycoproteins / Q000737:chemistry*; D009844:Oligosaccharides / Q000737:chemistry; D051381:Rats; D011956:Receptors, Cell Surface / Q000737:chemistry*; D015398:Signal Transduction / Q000502:physiology*; D020349:Surface Plasmon Resonance; D034421:Sus scrofa
D015815:Cell Adhesion Molecules; D029721:Drosophila Proteins; D053823:Hedgehog Proteins; D006493:Heparin; D006497:Heparan Sulfate; D008562:Membrane Glycoproteins; D009844:Oligosaccharides; D011956:Receptors, Cell Surface; C511591:Cdon protein, rat; C465570:Shh protein, mouse; C510880:iHog protein, Drosophila