Dynamic Structure of Biosupramole cular System.

本项目的目的是利用多相电子自旋共振谱对生物超分子体系进行细致和准确的研究。我们进一步尝试了用ESR成像方法分析超分子结构。在这个项目的第二年，我们集中在两个研究项目上，即生物超系统的动态结构，以及生物氧合计量学和生物动力学。多种ESR波谱的组合，即连续X波段、矢量、脉冲多维ESR、CW-ESR成像和脉冲-ESR成像。在1-250 GHz的不同频率水平上应用ESR波谱，我们虚拟地测定了分子有序性、流动性、链倾斜、头基协作性以及这些性质在不同相变时的变化。我们进一步应用了…将更多的载体ESR方法引入到由脂质-蛋白质复合体组成的体系中，并深入研究了蛋白质-脂质的相互作用，包括蛋白质对双层结构的“硬化效应”和“无序效应”。随着250 GHz(9特斯拉)远红外ESR光谱仪的建成，我们将ESR研究扩展到了高频和高场区域。高场提高的光谱分辨率使我们能够准确地测量磁张量，准确地确定取向势和有序张量，并更准确地研究脂-蛋白质相互作用。通过对宽频率范围(250 GHz)的自旋弛豫的比较研究，可以获得关于生物膜动态结构的更详细的信息。特别是，250 GHz的超高场ESR是这类复杂生物膜系统动力学研究的标志性成就。其次，我们针对生物氧测量以及生物药物的动力学进行了研究。常规的电子自旋共振技术很难检测到具有丰富浓度和合适的驰豫时间的生物活性物质。我们将正在开发的新技术应用于生物药物和生物氧的电子自旋弛豫实验，旨在显著提高光谱分辨率。其中包括脉冲L波段电子自旋回波技术。我们广泛地利用了这项新技术。同时，利用体内电子自旋共振测定仪对生物制剂的结构特征进行了表征。随着我们用于小动物实验的新ESR谐振器的完成，我们将把我们的ESR研究扩展到体内。较少

The present project is aimed at careful and accurate studies of the biosupra-molecular system using the multi-phase electron spin resonance spectroscopies. We further have attempted an analysis of supra-molecular structure using the ESR imaging method. For the second year of this project, we focused on the two research project, i.e., dynamic structure of biosupra-systems, and biooxymetry as well as dynamics of bioradicals.Firstly, we performed the comprehensive study on the supra-molecular structure via. combination of multiple-ESR spectroscopies i.e., CW X-band, vector, pulse multi-dimensional ESR,CW-ESR imaging and pulsed-ESR imaging. Application of ESR spectroscopies at various frequency level from 1 to 250 GHz on the well-aligned and thick multilayrs of such systems as partially hydrated phospholipid bilayrs, we virtually determined molecular ordering, fluidity, chain tilt, headgroup cooperativity, and how these properties change at the various phase transitions. We further applied … More vector ESR method to a system consisted of lipid-protein complex, and to study in-depth the protein-lipid interaction, including the "hardening-effect"vs. the "disordering-effect" of the protein on the bilayr structure. We extended our ESR studies into the high-frequency and high-field regime with the completion of 250 GHz (9 Tesla) far-infrared ESR spectrometer. The increased spectral resolution from the high fields enabled us to make accurate measurements of magnetic tensors, to accurately determine orienting potentials and ordering tensors and to more accurately study the lipid-protein interaction.Comparative studies of spin-relaxation over a wide range of frequencies(250 GHz)lead to more detailed information on the dynamic structure of biomembranes. In particular, the ultra-high field ESR at 250 GHz is the land mark attainment for such the dynamic study in complex biomembranes systems.Secondly, we aimed at biooxymetry as well as dynamics of bioradicals. The conventional ESR sorely detects few bioladicals having a rich concentration and appropriate relaxation times. We applied developing new techniques for electron-spin relaxation experiments on bioradicals and biooxgens, which are designed to significantly improve spectral resolution. These include a pulsed L-band electron-spin-echo technique. We extensively exploited this new technique. Also, in vivo ESR instrument was used to delineate structural features of bioradicals. We shall be extending our ESR studies into in vivo regime with the completion of our new ESR resonator for small animal experiments. Less