TARGETING HER-2 PROTEIN FOR BREAST CANCER USING COMPUTATIONAL APPROACH

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 人表皮生长因子受体2（HER 2）是人表皮生长因子受体激酶（其他成员包括EGFR或HER 1、HER 3和HER 4）的成员，参与细胞生长和分化的信号级联。已经确定HER 2介导的异源二聚化在癌症中具有重要意义。已知在癌细胞中发生信号通路的失调和HER 2的过表达。我们设计了抑制细胞生长信号的肽模拟物。中心假设是基于HER 2-赫赛汀复合物的结构设计的肽模拟物将抑制HER 2介导的细胞生长信号。为了理解由HER 2蛋白介导的信号传导的分子机制，使用肽模拟物HERP 5。本研究的目的是（a）评价HERP 5与细胞表面上的HER 2的结合特性;（B）评价荧光标记的HERP 5与HER 2蛋白的结构域IV的结合; c）使用结构生物学技术评价HERP 5及其类似物与HER 2胞外结构域的结合;以及d）使用计算方法模拟HER 2与其他受体的二聚化。荧光标记的HERP 5与HER 2蛋白的结合通过荧光测定、显微镜和圆二色光谱进行评价。结果表明，HERP 5与HER 2蛋白的胞外区结合。使用蛋白质-蛋白质对接方法提出了HER 2-EGFR二聚化和可能被HERP 5肽模拟物阻断的模型。未来的研究将集中在HER 2蛋白的表达，纯化，并使用表面等离子体共振技术和结构生物学方法阻断HER 2-EGFR相互作用。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Human epidermal growth factor receptor 2 (HER2) is a member of the human epidermal growth factor receptor kinases (other members include EGFR or HER1, HER3, and HER4) that is involved in signaling cascades for cell growth and differentiation. It is well established that HER2-mediated heterodimerization has important implications in cancer. Deregulation of signaling pathways and overexpression of HER2 is known to occur in cancer cells. We have designed peptidomimetics that inhibit signaling for cell growth. The central hypothesis is that peptidomimetics designed based on the structure of the HER2-herceptin complex will inhibit the HER2-mediated signal for cell growth. To understand the molecular mechanism of signaling mediated by HER2 protein, a peptidomimetic HERP5 was used. Thea objectives of this study are (a) to evaluate the binding properties of HERP5 to HER2 on the cell surface; (b) to evaluate the binding of fluorescently labeled HERP5 to domain IV of HER2 protein; c) to evaluate the binding of HERP5 and its analogs with HER2 extracellular domain using structural biology techniques; and d) to model the dimerization of HER2 with other receptors using computational methods. Binding of fluorescently labeled HERP5 to HER2 protein was evaluated by fluorescence assay, microscopy, and circular dichroism spectroscopy. Results indicated that HERP5 binds to the extracellular region of the HER2 protein. A model was proposed for HER2-EGFR dimerization and possible blocking by HERP5 peptidomimetic using a protein-protein docking method. Future studies will be focused on HER2 protein expression, purification, and blocking of HER2-EGFR interactions using surface plasmon resonance technique and structural biology methods.