STRUCTURE AND EXPRESSION OF COMPLEMENT GENES

补体基因的结构和表达

• 批准号: 2444524
• 负责人: Ronald T Ogata
• 金额: $ 27.7万
• 依托单位: MEDICAL BIOLOGY INSTITUTE
• 依托单位国家: 美国
• 财政年份: 1981
• 资助国家: 美国
• 起止时间: 1981-04-01 至 1999-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2444524
• 关键词: complement; complement pathway; gene expression; gene mutation; intermolecular interaction; laboratory mouse; nucleic acid sequence; protein sequence; protein structure function; synthetic peptide; tissue /cell culture

Over the past 10 years, recombinant DNA cloning and sequencing studies have elucidated the primary structures of the complement protein family that is composed of components C3, C4, and C5. This application proposes to use this sequence information, together with protein expression and mutagenesis methods, and a peptide inhibition strategy to probe the structural basis for the most important functional property shared by these 3 proteins: activation by proteolytic cleavage. Despite having very similar sequences at their activation sites, C3, C4, and C5 are specifically cleaved by distinct proteases. The proposed studies are aimed at identifying the structural features of C3 and C5 that are important for recognition by their specific proteases. The mutational strategy to be used focuses on regions marked by length polymorphisms (indels) in this protein family. This strategy was chosen because indels are usually associated with loops on the protein surface, and surface loops or turns are, in general, likely to be involved in a variety of intermolecular recognition events. Indels may play an important role in the evolution of distinct functions among members of a protein family. In providing a rationale for identifying the protease recognition sites on C3 and C5, this strategy suggests a comprehensive view of the structures of these proteins which combines what we know of their primary structures, the structures of their genes (indels are often found at intron-exon junctions), and the functional properties of the native proteins. Hence, the proposed studies also provide a test of this view. The long-term goal of this research program is to identify, for each member of this family, the structural features that together form their unique biochemical and functional properties. This information will provide detailed molecular insights into how these proteins function, and into complement function in general, as these proteins interact directly with most other complement proteins, and are the focus of complement activation, regulation, and complement receptor-mediated cellular interactions. This insight into complement function may aid in the design of intervention strategies such as the use of synthetic peptide inhibitors in situations where complement activation is undesirable, such as in chronic inflammation and in the hyperacute rejection associated with xenogeneic tissue transplantation.

在过去的10年里，重组DNA克隆和测序研究 阐明了补体蛋白家族的一级结构 它由组分C3、C4和C5组成。此应用程序建议 要使用该序列信息，连同蛋白质表达和 诱变方法和多肽抑制策略来探索 共享的最重要的功能属性的结构基础 这3种蛋白质：通过蛋白水解性裂解激活。尽管有 它们的激活位点C3、C4和C5非常相似的序列是 被不同的蛋白水解酶特异性地切割。建议进行的研究包括 旨在确定C3和C5的结构特征 对于其特定的蛋白酶的识别很重要。 要使用的突变策略主要集中在长度标记的区域 这个蛋白质家族的多态(INDELs)。这一战略被选择了 因为INDELs通常与蛋白质表面的环相关联， 而曲面环路或转弯通常很可能涉及 各种分子间识别事件。Indels可能会扮演一个 在成员之间不同职能的演变中发挥重要作用 一个蛋白质家族。为鉴定该酶提供了一个理论基础 C3和C5上的识别站点，这一策略建议 结合我们所知的这些蛋白质的结构的观点 它们的一级结构，它们的基因结构(INDELs通常是 发现于内含子-外显子连接处)，以及 天然蛋白质。因此，拟议的研究也是对这一点的检验。 查看。 这项研究计划的长期目标是为每一个 这个家族的成员，这些结构特征共同构成了他们 独特的生化和功能特性。此信息将 提供对这些蛋白质如何发挥作用的详细分子洞察，以及 到补体功能，因为这些蛋白质直接相互作用 与大多数其他补体蛋白一起，是补体的焦点 激活、调节和补体受体介导的细胞 互动。这种对补体功能的洞察可能有助于 设计干预策略，如使用合成肽 补体激活不可取的情况下的抑制剂，如 在慢性炎症和相关的超急性排斥反应中 异种组织移植。