MEMBRANE BIOGENESIS AND MEMBRANE FUSION

膜生物发生和膜融合

• 批准号: 3291040
• 负责人: ANTHONY W SCOTTO
• 金额: $ 11.22万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-12-01 至 1989-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3291040
• 关键词: electron microscopy; liposomes; membrane fusion; membrane model; membrane reconstitution /synthesis; membrane structure; phospholipids; vesicle /vacuole

The object of this proposal is to continue the study of two aspects of our recent discovery in the field of membrane biology. The first, is the spontaneous insertion of integral membrane proteins into preformed bilayers and the second is the membrane fusion that is catalyzed by the same methodology. We have observed that the presence of impurities in the bilayer of preformed vesicles triggers both the incorporation of purified integral membrane proteins as well as the fusion of unilamellar proteoliposomes when the phospholipids are in the gel state. The rapid fusion of liposomes and proteoliposomes by this manipulation of the phospholipid bilayer presents an ideal model system for the study of the cellular membrane fusion at the level of the phospholipid bilayer. We propose to utilize this system to investigate several concepts in membrane biology while we extend the applicability of this method for reconstruction studies. We plan to construct proteoliposomes with several different membrane proteins by this procedure; some of the integral membrane proteins for this study will be selected to demonstrate a functional interaction within the newly formed membrane while others will be employed to modify the surface availability and characteristics of the proteoliposome. As a result of this aspect of the work, we expect to be able to construct a model cell membrane composed of several different integral membrane proteins in which many of the current concepts in cellular and membrane biology can be tested. Furthermore, the apparent ability to construct proteoliposomes of cellular dimension (7 microns) by this procedure will be further examined in an effort to design and construct a model cell of predetermined protein composition and lipid/protein ratio. The stability of these very large proteoliposomes of high lipid/protein ratio has exceeded our expectations and we believe that the proposed proteoliposomes of low lipid-to-protein ratio will provide a very stable vesicle which may represent the ideal model cell. The long range goals are two-fold with respect to the phenomenon we have discovered. We propose to determine whether the mechanism by which we have incorporated integral membrane proteins into preformed bilayers represents the in vivo participation of the phospholipid in cellular membranes. We will determine too whether the specificity of membrane fusion among biological membrane is regulated in part by the proposed mechanism for the fusion of proteoliposomes in this procedure.

该提案的目的是继续研究我们的两个方面 膜生物学领域的最新发现。 第一个，是 将完整的膜蛋白自发插入到预先形成的双层中 第二种是由相同物质催化的膜融合 方法论。 我们观察到，杂质的存在 预制囊泡的双层触发纯化的 整合膜蛋白以及单层融合 当磷脂处于凝胶状态时，形成蛋白脂质体。 快速的 通过这种操作将脂质体和蛋白脂质体融合 磷脂双层为研究提供了一个理想的模型系统 磷脂双层水平的细胞膜融合。 我们 提议利用该系统来研究膜中的几个概念 生物学，同时我们扩展了这种方法在重建方面的适用性 研究。 我们计划构建具有几种不同的蛋白脂质体 通过该程序的膜蛋白；一些整合膜蛋白 本研究将被选择来展示功能相互作用 在新形成的膜内，而其他膜将被用来修改 蛋白脂质体的表面可用性和特征。 作为一个 这方面工作的结果，我们期望能够构建一个 由几种不同的整体膜组成的模型细胞膜 蛋白质中包含细胞和膜中许多当前的概念 可以测试生物学。 此外，明显的构建能力 通过此程序，细胞尺寸（7微米）的蛋白脂质体将是 进一步研究以设计和构建一个模型单元 预定的蛋白质组成和脂质/蛋白质比率。 稳定性 这些具有高脂质/蛋白质比率的非常大的蛋白脂质体 超出了我们的预期，我们相信所提出的蛋白脂质体 低脂质与蛋白质比率将提供非常稳定的囊泡，这可能 代表理想的模型细胞。 长期目标有两个方面： 尊重我们发现的现象。 我们建议确定 我们整合整合膜的机制是否 蛋白质进入预形成的双层代表体内参与 细胞膜中的磷脂。 我们也将确定是否 生物膜之间膜融合的特异性受调节 部分由所提出的蛋白脂质体融合机制决定 程序。