ROLE OF CYTOCHROME B IN NEUTROPHIL SUPEROXIDE PRODUCTION

本提案的长期目标是确定 人类中性粒细胞产生超氧化物的分子基础。 拟议的调查将侧重于人类的作用 中性粒细胞色素B-559在降低 相当于炎症部位的分子氧。 了解这种传递的分子机制及其 监管将提供必要的关键信息， 在分子水平上理解杀微生物剂的杀伤作用， 人类中性粒细胞的错误组织损伤功能。 在 此外，它将有助于奠定基础， 慢性肉芽肿病的基因治疗。 更具体地说，该提案概述了以下战略： 细胞色素未知结构参数的测定 b559，例如亚基之一的氨基酸序列（22 千道尔顿轻链），血红素辅基的定位， 分子与膜的关系，以及结构 伴随超氧化物生成激活的变化; 2） 生物化学、免疫学和生物物理学测定 要求细胞色素B-559作为 中性粒细胞中的超氧化物生成系统; 3） 分布、流动性和生化状态的测定 细胞色素B-559在静息和活化的人 中性粒细胞，以检验有关其作用机制的假设 在组织损伤中的功能作用; 4）超氧化物的重建 使用分离和纯化的b-细胞色素和其他 为了创建一个模型系统， 研究质膜电子传递所需 超氧化物产生; 6）产生额外的免疫和 结构和功能的生化探针，以促进 中性粒细胞超氧化物产生的分子解剖。 这项工作可能有助于了解 超氧化物生成系统可以在外部操作， 增强宿主的防御能力， 可触及部位，如肺组织。

The long term objective of this proposal is to determine the molecular basis for superoxide production in human neutrophils. The proposed investigation will focus on the role of human neutrophil cytochrome b-559 in the delivery of reducing equivalents to molecular oxygen at the sites of inflammation. Understanding the molecular mechanism of this delivery and its regulation will provide crucial information necessary for understanding, at the molecular level, the microbicidal killing and misdirected tissue injury functions of human neutrophils. In addition, it will aid in laying the foundation for an ultimate genetic cure of chronic granulomatous disease. More specifically, this proposal outlines strategies for: 1) determination of unknown structural parameters of cytochrome b559 such as amino acid sequence of one of the subunits (22 kilodalton light chain), localization of the heme prosthetic group, relationship of the molecule to the membrane, and structural changes accompanying activation of superoxide production; 2) biochemical, immunological, and biophysical determination of the requirement for cytochrome b-559 as the terminal component of the superoxide generating system in the neutrophil; 3) determination of the distribution, mobility, and biochemical state of the cytochrome b-559 in resting and activated human neutrophils to test hypotheses concerning its mechanism of action and functional role in tissue injury; 4) reconstitution of superoxide production using isolated and purified b-cytochrome and other components of the neutrophil in order to create a model system to study plasma membrane electron transport required for superoxide production; 6) production additional immunological and biochemical probes of structure and function to facilitate the molecular dissection of neutrophil superoxide production. Potentially this work will contribute to understanding how the superoxide generating system can be externally manipulated to enhance host defenses but reduce inflammation at potentially accessible sites such as lung tissue.