PHYSICAL BIOCHEMISTRY, PROTEINS, & MOLECULAR RECOGNITION

我们研究的长期目标是理解 蛋白质序列与高级结构和功能之间的关系。在 在过去的五年里，我们研究了蛋白质内部的相互作用；具体地说， 电子交易者N-端和C-端螺旋之间的界面 蛋白质细胞色素c(CC)。在未来的五年里，我们希望用我们的 向新方向发展的专业知识和研究 蛋白质也是。 了解蛋白质之间的相互作用是理解 信号转导，一个几乎所有生物都必须的过程 从发育到癌症的过程。了解内部的交互 蛋白质对于解释来自基因组计划的数据和 设计具有医学用途的新型蛋白质。理解 生物电子转移很重要，因为人类的遗传缺陷 电子转移蛋白被认为在衰老和 退行性疾病。 在蛋白质之间。将研究三种复合体：CC/细胞色素c 过氧化物酶(CCP)、CC/黄色素b2和CC/细胞色素b5。目前 其中任何一个都没有详细的平衡热力学数据。 因此，拟议的研究将导致新的和重要的 关于分子识别的信息。均衡绑定数据将是 用等温滴定量热法和电子转移得到 费率将由我们的合作者Millett&Durham衡量。三 假设将被检验：1)疏水接触控制强度 结合，但离子相互作用控制电子转移的速度； 以前提出的络合物结构模型中的接触是 对结合和电子转移都很重要；3)弱CC结合 CCP上的位置决定了电子转移。绑定数据也将是 用来检验最近几个关于表面积和 蛋白质复合体形成中的溶剂化作用。 在蛋白质中。我们将测试人们普遍认为熔化的水珠 包含很少(如果有的话)特定的本地远程交互作用。我们有 最近发现N-端和C-端螺旋之间的相互作用 持续存在于熔化的球体中。我们现在建议将交互映射到 血红素、60s螺旋和C-末端螺旋。均衡性 变性的热力学将用差动法测量。 扫描量热法。

The long range goal of our research is to understand the relationships between protein sequence and higher order structure and function. In the past five years we examined interactions within a protein; specifically, the interface between the N- and C-terminal helices of the electron trader protein cytochrome c (Cc). In the next five years we wish to use our expertise to move in a new direction and study interactions between proteins as well. Understanding interactions between proteins is the key to understanding signal transduction, a process essential to nearly all biological processes from development to cancer. Understanding interactions within proteins is crucial for interpreting the data from genome projects and designing novel proteins with medically useful functions. Understanding biological electron transfer is important because genetic defects in electron transfer proteins are thought to play a role in aging and in degenerative diseases. Between proteins. Three complexes will be examined: Cc/cytochrome c peroxidase (CCP), Cc/flavo-cytochrome b2, and Cc/cytochrome b5. Currently there are no detailed equilibrium thermodynamic data on any of these complexes, so the proposed research will lead to new and important information about molecular recognition. Equilibrium binding data will be obtained using isothermal titration calorimetry and electron transfer rates will be measured by our collaborators Millett & Durham. Three hypotheses will be tested: 1) hydrophobic contacts control the strength of binding, but ionic interactions control the rate of electron transfer; 2) contacts in the previously proposed structural models of the complexes are important for both binding and electron transfer; 3) a weak Cc binding site on CCP dominates electron transfer. The binding data will also be used to test several recent hypotheses about the role of surface area and solvation in protein complex formation. Within proteins. We will test the widely held belief that molten globules contain few, if any, specific native long range interactions. We have recently shown that the interaction between the N- and C-terminal helices persists in the molten globule. We now propose to map interactions between the heme, the 6Os helix and the C-terminal helix. The equilibrium thermodynamics of denaturation will be measured using differential scanning calorimetry.