Zhang Fuming, McLellan Jason S, Ayala Alondra M, Leahy Daniel J, Linhardt Robert J
Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.
Biochemistry. 2007 Apr 3;46(13):3933-41. doi: 10.1021/bi6025424. Epub 2007 Mar 10.
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.
硫酸乙酰肝素（HS）蛋白聚糖（PGs）与多种细胞外信号蛋白相互作用，从而在许多生理过程的调节中发挥重要作用。这些相互作用对于正常信号转导和信号分子组织分布的调节都很重要。在本研究中，我们使用表面等离子体共振（SPR）来研究HS和结构相关的肝素与刺猬信号通路中蛋白质的相互作用。SPR分析表明，肝素以不同亲和力与蛋白质刺猬（Hh）、干扰刺猬（Ihog）、与钙调蛋白相关/被癌基因下调（CDO）和音猬因子（Shh）的活性片段结合。溶液竞争研究表明，能够与Ihog相互作用的肝素寡糖的最小尺寸大于四糖，与Shh相互作用的最小尺寸大于八糖。与肝素相比，Ihog和Shh对HS的亲和力低于对肝素的亲和力，而CDO和Hh与HS的结合可忽略不计。这项研究清楚地表明，Shh和Ihog是肝素和HS结合蛋白，并且这两种分子优先结合具有高水平硫酸化的肝素或HS。
