PEPTIDES BASED ON ACTIVE SITES OF ACTIN BINDING PROTEINS

拟议合作的总体目标是提供信息 关于巨噬细胞等活动细胞内的结构变化， 当这些细胞对 细胞外信号。细胞的运动性是这种生理所必需的 吞噬、凝血时的血小板反应等过程， 伤口愈合和神经发育。了解链接 细胞信号和运动之间的关系对于理解 导致运动受损或不受控制的缺陷和 扩散。这项工作的重点是肌动蛋白细丝的切断 明胶蛋白、绒毛蛋白和其他肌动蛋白结合蛋白，如 受多聚磷脂酰肌醇(PPI‘s)调节的Profilin。 多磷肌醇是细胞中普遍存在的磷脂成分。 通过几种不同的方法进行磷酸化或水解的膜 酶参与了许多信号转导途径。父辈 此协作所基于的项目涉及生化和 肌动蛋白和其他蛋白质网络的生物物理研究，旨在 确定如何重塑此类网络以及如何重塑这些网络 参与制作动作。此扩展将允许详细的 多聚磷脂酰肌醇与蛋白质结合部位的分析 这种结合所引起的蛋白质内部的结构变化。 这项建议的具体目标是研究 基于序列合成肽的聚磷脂酰肌醇 在潜在的PPI结合位点的蛋白质中，通过研究 蛋白水解性衍生的蛋白质片段或突变体。的优势 研究合成的小分子多肽的结构可以是 比完整的蛋白质更严格地研究，在某些情况下，他们的 溶液结构可以完全由核磁共振和其他方法确定 方法如家长赠款中所讨论的。多肽合成需要 专业技能和设备与那些 需要研究细胞生物学或多肽对 例如，明胶/PPI相互作用，因此父母拨款 没有关于多肽合成的规定。与以下公司合作的机会 一个专门研究多肽的有机合成实验室扩大了 可应用于研究生物信息素调控的实验范围 肌动蛋白结合蛋白，将提高精确度 可以确定PPI调节蛋白质所需的位点。这个 后一种可能性可能与 调节PPI代谢或细胞骨架的药物 活体重塑。

The overall goal of the proposed collaboration is to provide information about how structural changes within motile cells such as macrophages, platelets and lymphocytes are achieved when these cells respond to extracellular signals. Cell motility is necessary for such physiologic processes as phagocytosis, platelet response during blood coagulation, wound healing, and neurologic development. Understanding the link between cell signalling and motility is important for understanding the defects that causes impaired or uncontrolled movements and proliferation. This work focuses on the actin filament-severing proteins gelsolin, villin, and other actin-binding proteins such as profilin that are regulated by polyphosphoinositides (PPI's). Polyphosphoinositides are ubiquitous phospholipid components of the cell membrane whose phosphorylation or hydrolysis by several different enzymes is involved in many signal transduction pathways. The parent project on which this collaboration is based involves biochemical and biophysical studies of actin and other protein networks, designed to determine how such networks are remodeled and how their remodeling may be involved in producing motion. This extension will allow detailed analysis of the site on proteins to which polyphosphoinositides bind and of the structural changes within the protein caused by this binding. The specific aim of this proposal is to examine interactions of polyphosphoinositides with synthetic peptides based on the sequences within proteins implicated as potential PPI-binding sites by studies of proteolytically-derived protein fragments or mutants. The advantage of studying small synthetic peptides is that their structures can be studied more rigorously than intact proteins, and in some cases their solution structures can be completely determined by nmr and other methods as discussed in the parent grant. Peptide synthesis requires specialized skills and equipment that are very different from those required to study cell biology or the effects of the peptides on, for example, gelsolin/PPI interactions, and therefore the parent grant made no provision for peptide synthesis. The opportunity to collaborate with a laboratory of organic synthesis that specializes in peptides expands the range of experiments that can be applied to study the regulation of actin-binding proteins and will increase the precision with which the sites necessary for protein regulation by PPI's can be defined. The latter possibility could potentially be relevant to the design of pharmacologic agents that modulate PPI-metabolism or cytoskeletal remodeling in vivo.