Structural Specificity of Heparan Sulfate for Herpes Infections

硫酸乙酰肝素是一种高度硫酸化的多糖，具有非常复杂的糖结构。乙酰肝素 硫酸盐大量存在于细胞表面和细胞外基质中， 在广泛的生理和病理生理功能中的作用。我们建议理解 特异性磺化糖序列有助于单纯疱疹病毒感染。的 硫酸乙酰肝素与单纯疱疹病毒包膜蛋白的结合代表了 感染.最近的研究表明，一个特定的3-O-硫酸乙酰肝素硫酸盐起着至关重要的作用， 帮助单纯疱疹病毒1的进入。这种独特的硫酸乙酰肝素亚型是由 几种硫酸乙酰肝素3-0-磺基转移酶同种型（3-OST）。我们计划调查嫌疑人 3-OST的识别机制。我们还将研究如何制备多糖或 具有独特磺化模式的寡糖，以提高抑制疱疹的功效和选择性 单纯感染本项目提出了三个具体目标：具体目标1是调查 3-OST底物识别机制。我们计划对3-OST-5进行晶体结构研究， 定点诱变。其次，我们计划转化3-OST-1，一种不产生HSV的酶， 进入受体，至通过随机诱变产生HSV进入受体的3-OST-3样酶。 具体目标2是开发一种酶促方法来合成八糖和多糖， 携带关键的3-0-磺基葡糖胺残基。我们最近的数据表明，这种方法使我们能够 合成足够量的多糖以研究其抑制单纯疱疹的效果 病毒感染。具体目标3是确定合成的化合物对小鼠的抗肿瘤作用的功效。 单纯疱疹病毒感染我们计划确定它们对进入的影响以及对 单纯疱疹病毒对靶细胞的作用。我们还计划研究这些化合物对 单纯疱疹病毒通过不同的细胞受体进入。我们的研究结果可能会导致一种新的方法， 治疗单纯疱疹病毒感染，提高对HS生物合成的基本认识， 特定的磺化模式。

Heparan sulfate is a highly sulfated polysaccharide with very complicated saccharide structures. Heparan sulfate is present on the cell surface and in the extracellular matrix in a large quantity, and plays important roles in a wide range of physiological and pathophysiological functions. We propose to understand the contribution of specific sulfonated saccharide sequences to assist herpes simplex virus infections. The binding of heparan sulfate to the herpes simplex virus envelope proteins represents the initial step of viral infections. Recent studies reveal that a specific 3-O-sulfated heparan sulfate plays an essential role for assisting the entry of herpes simplex virus 1. This unique subtype of heparan sulfate is biosynthesized by several heparan sulfate 3-0-sulfotransferase isoforms (3-OST). We plan to investigate the susbtrate recognition mechanism of 3-OST. We will also investigate how to prepare the polysaccharides or oligosaccharides with unique sulfonation patterns to improve the efficacy and slectivity for inhibiting herpes simplex infections. Three specific aims are proposed in this project: Specific Aim 1 is to investigate the substrate recognition mechanism of 3-OST. We plan to conduct a crystal structure study on 3-OST-5 and site-directed mutagenesis. Second, we plan to convert 3-OST-1, an enzyme that does not produce an HSV entry receptor, to a 3-OST-3-like enzyme that generates an HSV entry receptor by random mutagenesis. Specific Aim 2 is to develop an enzymatic approach to synthesize octasaccharides and polysaccharides that carry the critical 3-0-sulfo glucosamine residues. Our recent data suggest that this approach allows us to synthesize the polysaccharides in sufficient amounts for studying their effects on inhibiting herpes simplex virus infections. Specific Aim 3 is to determine the efficacy of the synthesized compounds on inhibitng herpes simplex infections. We plan to determine their effects on the entry as well as on the binding of herpes simplex virus to the target cells. We also plan to investigate the efficacy of these compounds on the entry of herpes simplex virus via different cellular receptors. Our results could lead to a novel approach to treat herpes simplex virus infections and improve the basic understanding on the biosynthesis of HS with specific sulfonation patterns.