LECTIN-LIKE PROPERTIES OF AMELOGENINS

描述(改编自调查者摘要)：长期目标 这项建议的目的是确定釉原蛋白的性质和功能 其他釉质蛋白的糖残留物，以及细胞表面的糖偶联物。这个 中心假设是釉原蛋白具有凝集素样属性，这是 介导功能性蛋白质-碳水化合物与基质糖蛋白的相互作用 或细胞表面糖结合物在基质内或牙本质牙釉质处 交界处(DEJ)。首席调查员实验室的初步数据 已经确定了存在和釉原蛋白糖基结合基序位于 该分子的保守氨基末端区域。其他人已经建立了 釉原蛋白结构这一区域的突变会导致 临床釉质缺陷；釉质发生不全。(Collier等人，1997)。至 检验这一假设将调查以下五个具体目标。这个 第一个目标是确定釉原蛋白和釉原蛋白之间的特定相互作用 N-乙酰氨基葡萄糖(GlcNAc)和N-乙酰神经氨酸的结构类似物 酸(NeuAC)及其在哺乳动物中常见的糖苷键 糖蛋白和糖脂。凝集和竞争抑制研究 釉原蛋白与寡糖和糖共轭。(2)识别 牙釉质细胞外基质中与釉原蛋白结合的可能配体 “非釉原蛋白”糖蛋白组分。凝集素组织化学研究 非釉原蛋白及其免疫学和放射学评价 研究了釉原蛋白与这些蛋白的结合。(三)评估影响 碳水化合物-釉原蛋白在纳米球形成中的相互作用。的共轭 用电子力和原子力研究糖蛋白和釉原蛋白 显微镜。(4)评价富含GlcNAc/NeuAc的非釉原蛋白的作用 和糖蛋白类似物对生物矿化的影响 釉原蛋白体外实验。磷灰石的糖结合物和釉原蛋白的作用 对生物矿化作用进行了评估。(5)开发识别和识别模型 成牙本质细胞表面糖结合物与釉原蛋白的结合 并测定成釉蛋白衍生肽对人成釉细胞的影响。 体外成釉。建立了成纤维细胞模型和细胞表面 釉原蛋白相互作用及釉原蛋白多肽在慢性牙周炎中的作用 研究了反馈-信号通路。这些实验是合乎逻辑的 新发现的釉原蛋白凝集素样特性的研究进展 (Ravindranath等人)提交)，它们被假定为发挥功能作用 在正常的牙釉质生物矿化中。

DESCRIPTION (adapted from the Investigator's abstract): The long-term objective of this proposal is to determine the nature and function of amelogenins with sugar residues of other enamel proteins, and cell surface glycoconjugates. The central hypothesis is that amelogenins have lectin-like properties, which mediate functional protein-carbohydrate interactions with matrix glycoproteins or cell surface glycoconjugates within the matrix or at the dentine enamel junction (DEJ). Preliminary data from the Principal Investigator's laboratory have established the presence of and amelogenin glyco-binding motif located in the conserved amino terminal region of the molecule. Others have established that a mutation in this region of the amelogenin structure results in the clinical enamel defect; amelogenesis imperfecta. (Collier et al., 1997). To test this hypothesis the following five specific aims will be investigated. The first aim is to identify specific interactions between amelogenins and structural analogs of N-acetyl glucosamine (GlcNAc) and N-acetyl neuraminic acid (NeuAC) and their glycosidic linkages commonly found in mammalian glycoproteins and glycolipids. Agglutination and competitive inhibition studies of amelogenins with oligosaccharides and glycoconjugates. (2) To identify putative ligands for amelogenin-binding in the extracellular enamel matrix "non-amelogenin" glycoprotein fractions. The lectin histochemistry of non-amelogenin proteins and immunological and radiometric assessment of amelogenin binding to these proteins is studied. (3) To assess the influence of carbohydrate-amelogenin interactions on nanosphere formation. Conjugates of glycoproteins and amelogenins are studied employing electron and atomic-force microscopy. (4) To evaluate the effects of GlcNAc/NeuAc-rich non-amelogenins and glycoprotein analogs on biomineralization in the presence and absence of amelogenin in vitro. The effects of glycoconjugates and amelogenins of apatite biomineralization are assessed. (5) To develop a model for the recognition and binding of amelogenins with cell surface glycoconjugates of odontoblasts and ameloblasts and to determine the effects of amelogenin-derived peptides on amelogenesis in vitro. A fibroblast model is developed and cell-surface amelogenin interactions and the putative role of amelogenin peptides in a feedback-signaling pathway are investigated. These experiments are a logical extension of the newly identified lectin-like properties of amelogenins (Ravindranath et al. Submitted), which are postulated to play a functional role in normal enamel biomineralization.