STRUCTURE, DYNAMICS AND FUNCTION OF CHAPERONE DOMAINS

现在了解到体内蛋白质折叠是由一类特殊的 被统称为伴侣蛋白的辅助蛋白。 建议的工作 这项资助将集中在70 kDa热休克蛋白家族上 热休克蛋白70（Hsp 70），从细菌到哺乳动物都是保守的。 将蛋白质 参与肽翻译的最早阶段，并与新生的 肽链和预定转运到细胞的肽链 细胞器 此外，这些蛋白质结合到蛋白质受损， 热和其他压力（热休克）或突变。 在这个拨款申请中，我们建议确定三维 结构和动力学的肽结合域的两个 真核细胞Hsp 70蛋白，细胞质中发现的Hsc和BiP 内质网的蛋白质。 此外， 将研究这些蛋白质与小肽的复合物。 多重 核，多维核磁共振方法将被使用;信息将 与功能相关，使用定点诱变， 合作时尚 这些研究的目的是了解的基础上， 这些伴侣蛋白的功能。 有了这些信息，我们可以推断 并合理化了分子伴侣对疏水性的表观特异性， 缩氨酸 我们还将深入了解可能的构象变化 调节热休克蛋白70对其靶点的亲和力。 的结构 结合的肽将指示它们的结合模式 解决了Hsp 70是否只是溶解未折叠的 蛋白质或蛋白质折叠的初始阶段是否发生在它们的 结合裂缝 动态信息将是 解释过程。 蛋白质折叠是细胞功能的基础，只有在适当的条件下， 并及时折叠蛋白质，使细胞能够执行其复杂的 调节功能和生长周期。 在结构上的洞察 在体内蛋白质折叠的基础，将获得从拟议的 因此，研究与理解这些增长有关。 周期及其干扰。

Protein folding in vivo is now understood to be assisted by a special class of helper proteins collectively known as chaperones. The work proposed in this grant will concentrate on the family of 70 kDa heat shock proteins (Hsp70), which is conserved from bacteria to mammals. The proteins are involved in the earliest stages of peptide translation and bind to nascent peptide chains and peptide chains destined for transport to cellular organelles. In addition, these proteins bind to proteins damaged by thermal and other stress (heat shock) or mutation. In this grant application, we propose to determine the three-dimensional structures and the dynamics of the peptide binding domains of two eukaryotic Hsp 70 proteins, the Hsc found in the cytosol and the BiP protein of the endoplasmic reticulum. In addition, the structures of complexes of these proteins with small peptides will be studied. Multi- nuclear, multi-dimensional NMR methods will be used; the information will be correlated with function using site-directed mutagenesis in a collaborative fashion. The objective of these studies is to gain insight in the basis of the function of these chaperone proteins. With this information, we may infer and rationalize the apparent specificity of the chaperones for hydrophobic peptides. We will also gain insight in possible conformational changes that modulate the affinity of Hsp70s for their targets. The structures of the bound peptides will indicate their mode of binding and will help resolve the question whether the Hsp70s are merely solubilizing unfolded proteins or if initial stages of protein folding are taking place in their binding cleft. The dynamic information will be integral part of the interpretation processes. Protein folding is very basic to cell functioning; it is only with properly and timely folding proteins that the cell can perform its complicated regulatory functions and growth cycles. The insight in the structural basis of in vivo protein folding that will be gained from the proposed studies is therefore of relevance to the understanding of these growth cycles and their disturbances.