BIOMOLECULE INTERACTIONS W/ FLUORESCENCE CORRELATION SPECTROSCOPY

蛋白质溶液动力学的稳态和稳态研究 时间分辨荧光法蛋白质寡聚体的形成和 配体缔合--两种蛋白质系统正在研究中：（1） rasp 2l癌基因产物和（2）可溶性毒液（Akistrodom 食鱼的& Crotalusatrox）和磷脂A2 s3。 (1)的 ras p2 l癌基因蛋白质的寡聚体结构和局部 它们的鸟嘌呤核苷酸结合位点的构象动力学是 正在用荧光标记的核苷酸进行研究。 全局 和当地的环境参数正在检查，以确定 溶液低聚物形式和相关的构象差异 各种ras p2 l蛋白的GTP-和GDP-形式之间的关系， 致癌突变体 荧光寿命和动态 正在获取极化数据。 (2)溶液中磷脂酶A2 从眼镜蛇毒液中分离的PLA 2似乎在配体上聚集， 磷脂和/或Ca++，而响尾蛇毒液中的PLA 2仍然是一种磷脂酶。 二聚体和来自胰腺的PLA 2作为单体存在。 的高度 这些酶之间的序列相似性和作用模式表明， 共同机制。 溶液的结构，配体的影响， 这种结构，以及寡聚体和酶功能之间的联系 通过荧光能量转移和动力学研究 极化

Investigation of Protein Solution Dynamics by Steady-State and Time- Resolved Fluorescence Methods Protein Oligomer Formation and Ligand Association--Two protein systems are being investigated: (1) the ras p2l oncogene products and (2) the soluble venom (Akistrodom piscovorous & Crotalus atrox) and phospholipone A2s3. (1) The oligomeric structure of the ras p2l oncogene proteins and the local conformational dynamics of their guanine nucleotide binding site is being investigated with fluorescently tagged nucleotides. Both global and local environmental parameters are being examined to define the solution oligomer form and the pertinent conformational differences between the GTP- and GDP-forms of the various ras p2l proteins and cancer-causing mutants. Fluorescence lifetimes and dynamic polarization data are being taken. (2) In solution phospholipase A2 (PLA2) isolated from Cobra venom appears to aggregate upon ligand, phospholipid and/or Ca++, while PLA2 from rattlesnake venom remains a dimer and PLA2 from pancreas exists as a monomer. The high degree of sequence similarity and modes of action among these enzymes suggests a common mechanism. The solution structure, the effect of ligands on this structure, and the link between the oligomer and enzyme function are being investigated by fluorescence energy transfer and dynamic polarization.