LECTIN-LIKE PROPERTIES OF AMELOGENINS

描述（改编自研究者摘要）：长期目的 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基和细胞表面糖缀合物。的 中心假设是釉原蛋白具有凝集素样性质， 介导与基质糖蛋白的功能性蛋白质-碳水化合物相互作用 或基质内或牙本质釉质处的细胞表面糖缀合物 结（DEJ）。主要研究者实验室的初步数据 已经确定了存在釉原蛋白糖结合基序， 分子的保守氨基末端区域。其他人已经建立了 釉原蛋白结构的这一区域的突变导致 临床牙釉质缺损;牙釉质发育不全。（Collier等人，1997年）。到 为了检验这一假设，将研究以下五个具体目标。的 第一个目的是鉴定釉原蛋白和 N-乙酰葡糖胺（GlcNAc）和N-乙酰神经氨酸的结构类似物 酸（NeuAC）及其糖苷键通常在哺乳动物中发现 糖蛋白和糖脂。凝集和竞争性抑制研究 釉原蛋白与寡糖和糖缀合物的结合。(2)以识别 细胞外釉基质中釉原蛋白结合的推定配体 “非釉原蛋白”糖蛋白级分。采用凝集素组织化学方法， 非釉原蛋白质和免疫学和放射性评估 研究了釉原蛋白与这些蛋白质的结合。(3)的影响进行评估 糖-釉原蛋白相互作用对纳米球形成的影响。的缀合物 糖蛋白和釉原蛋白的研究采用电子和原子力 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， 体外釉原蛋白。磷灰石的糖复合物和釉原蛋白的作用 生物矿化进行了评估。(5)为了开发一个识别模型， 釉原蛋白与成牙本质细胞的细胞表面糖缀合物的结合， 并确定釉原蛋白衍生肽对成釉细胞的作用。 体外成釉。建立成纤维细胞模型， 釉原蛋白的相互作用和釉原蛋白肽在一个 反馈信号通路进行了研究。这些实验符合逻辑 新鉴定的釉原蛋白的凝集素样性质的扩展 （Ravindranath等人提交），假定其发挥功能作用 在正常的釉质生物矿化中。

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.