THE STRUCTURES OF LARGE BIOMOLECULES AND BIOMOLECULAR SYSTEMS

在我实验室工作的MBR学生将有机会 在几个研究结构的项目中的一个或多个 生物分子和生物系统。他们将学习并独立地 实施生物医学和生物技术中使用的关键技术 研究。根据学生以前的经历和兴趣， 它们可能积极参与蛋白质的纯化，等电性 聚焦、定性和制备性聚丙烯酰胺凝胶电泳法， 离子交换层析和尺寸排除层析。特定的 项目可能涉及蛋白质结晶实验，单晶 X射线衍射实验，分子等计算方法 蛋白质/脂类的替代方法和分子模拟、制备 在电子显微镜下观察的单层系统的操作 电子显微镜、脂质体的制备及X射线散射 脂质体的实验。利用x射线衍射仪、电子显微镜 方法和计算方法，我们正在进行结构研究 白喉毒素片段A、B和艰难梭菌毒素A。 通过我们的研究，我们希望更好地了解， 亲水性分子，如细菌蛋白毒素，能够 跨细胞膜的转运及其对细胞的影响 目标。有关细菌蛋白毒素的结构信息也可能 帮助设计免疫毒素，这种分子可以有效地杀死特定的 癌症和相关疾病中的细胞。作为综合研究的一部分 基于脂质体的药物传递系统，我们正在使用x射线散射 方法研究AmBisome的结构性质 Vestar，Inc.AmBisome用于治疗系统性真菌感染 艾滋病发病期间或器官后的免疫抑制 移植手术。本研究的目的是阐明脂质体 治疗性药物的结构性质及其分子间相互作用 具有脂质双分子层的试剂。这将有助于我们更好地理解 脂质体的摄取、加工和反应性，并允许未来的理性 抗癌及相关药物最优给药系统的设计 疾病。

MBRS students working in my laboratory will have the opportunity to work on one or more of several projects that investigate structures of biomolecules and biological systems. They will learn and independently implement essential techniques used in biomedical and biotechnological research. Depending on the students' previous experiences and interests, they may be actively involved in protein purification, isoelectric focussing, qualitative and preparative polyacrylamide gel electrophoresis, ion exchange chromatography and size exclusion chromatography. Specific projects may involve protein crystallization experiments, single-crystal x-ray diffraction experiments, computational approaches such as molecular replacement methods and molecular modeling, preparation of protein/lipid monolayer systems for viewing under an electron microscope, operation of an electron microscope, preparation of liposomes and x-ray scattering experiments on liposomes. Using x-ray diffraction, electron microscopic methods and computational approaches, we are conducting structural studies on diphtheria toxin fragments A and B, and Clostridium difficile toxin A. From our studies we hope to better understand how high molecular weight, hydrophilic molecules such as bacterial protein toxins are capable of translocation across cellular membranes and effecting their cellular targets. Structural information about bacterial protein toxins may also aid in the design of immunotoxins, molecules efficient in killing specific cells in cancer and related diseases. As part of an integrated study of liposomal-based drug delivery systems, we are using x-ray scattering methods to investigate the structural properties of AmBisome, produced by Vestar, Inc. AmBisome is used to treat systemic fungal infections brought on by immune suppression during the onset of AIDS or after organ transplant surgery. The goal of this research is to elucidate liposome structural properties and the inter-molecular interactions of therapeutic agents with the lipid bilayer. This will help us to better understand liposome uptake, processing and reactivity, and allow for future rational design of optimal drug delivery systems to fight cancer and related diseases.