STRUCTURAL AND FUNCTIONAL ANALYSIS OF HUMAN IGFBP-4

人类 IGFBP-4 的结构和功能分析

• 批准号: 2015424
• 负责人: Xuezhong Qin
• 金额: $ 3.04万
• 依托单位: LOMA LINDA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-06-01 至 1999-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2015424
• 关键词: binding proteins; cell proliferation; gene expression; human tissue; insulinlike growth factor; osteoblasts; protein sequence; receptor binding; recombinant DNA; site directed mutagenesis

DESCRIPTION: This new small grant application will study the molecular mechanisms by which insulin-like growth factor binding protein-4 (IGFBP-4) inhibits the action of insulin-like growth factor (IGF). Previous studies from this laboratory indicate that IGFBP-4 inhibits the proliferation of osteoblasts by specifically preventing the binding of IGF to its membrane receptor. Preliminary data also suggest that the putative sequence essential for IGF binding is located in the region between Thr92 and Gln114. A series of well designed recombinant DNA approaches will be utilized to first localize the IGF binding domain within the IGF binding sequence using mutagenesis. It is proposed that the IGF binding domain of IGFBP-4 is localized within the variable non-conserved region of the gene. The second hypothesis proposes that the potency of IGFBP-4 analogs to inhibit osteoblast proliferation is directly proportional to their affinity for IGFs as well as their ability to compete with IGF receptor for IGF binding. Recombinant DNA techniques including DNA deletion, mutagenesis and polypeptide synthesis will be used to localize the IGF binding domain. Studies described in Aim 2 will then test the ability of resultant IGFBP-4 analogs to prevent IGF binding to its cell surface and a purified receptor. In addition, their ability to inhibit IGF-induced cell proliferation in bone cells will be determined. Completion of these studies will lead to the identification of the IGF binding domain in IGFBP-4 and to the future development of new IGF analogs that are resistant to IGFBP-4. In addition, these studies will contribute to future IGFBP-4 structure-function studies that may lead to the development of more potent IGFBP-4 analogs that can be used to treat certain cancerous cells whose proliferation is dependent on the autocrine/paracrine actions of the IGFs.

描述：这项新的小额赠款申请将研究分子 胰岛素样生长因子结合蛋白-4（IGFBP-4） 抑制胰岛素样生长因子（IGF）的作用。 以前的研究 来自该实验室的研究表明，IGFBP-4抑制了 通过特异性阻止IGF与成骨细胞膜的结合， 受体的 初步数据还表明， IGF结合所必需的蛋白位于Thr 92和Gln 114之间的区域。 将利用一系列精心设计的重组DNA方法， 首先使用以下方法将IGF结合结构域定位在IGF结合序列内 诱变 提出IGFBP-4的IGF结合结构域是 位于基因的可变非保守区内。 第二 一种假说提出IGFBP-4类似物抑制 成骨细胞增殖与其对IGFs的亲和力成正比 以及它们与胰岛素样生长因子受体竞争胰岛素样生长因子结合的能力。 重组DNA技术，包括DNA缺失、诱变和 多肽合成将用于定位IGF结合结构域。 目标2中描述的研究将测试所得IGFBP-4的能力， 类似物，以防止IGF结合到其细胞表面和纯化的受体。 此外，它们抑制IGF诱导的骨细胞增殖的能力 细胞将被确定。 完成这些研究后， IGFBP-4中IGF结合结构域的鉴定和未来 开发对IGFBP-4有抗性的新的IGF类似物。 此外，本发明还提供了一种方法， 这些研究将有助于未来IGFBP-4的结构-功能研究 这可能导致开发更有效的IGFBP-4类似物， 用于治疗某些癌细胞，其增殖依赖于 IGFs的自分泌/旁分泌作用。