PROMOTERS AND INHIBITORS OF MEMBRANE FUSION

膜融合的促进剂和抑制剂

• 批准号: 6181413
• 负责人: BRADLEY D. SMITH
• 金额: $ 15.79万
• 依托单位: UNIVERSITY OF NOTRE DAME
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2003-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6181413
• 关键词: biophysics; calorimetry; chemical conjugate; chemical structure function; chemical synthesis; conformation; hydropathy; inhibitor /antagonist; lipids; liposomes; membrane fusion; molecular polarity; phospholipids; polymers; stereochemistry; stop flow technique

The long-term goal of the program is to invent new materials that promote or inhibit the fusion of biological membranes. The work will bring practical as well as intellectual benefits to health and health science. From a practical perspective, the development of new fusion catalysts would be a welcome technological advance in the fields of hybridoma research, gene therapy and drug delivery; whereas, fusion inhibitors may be useful as novel therapeutic agents for a range of disease areas, especially opportunistic infection. There will be substantial intellectual contributions as the promoters and inhibitors are designed to test our current understanding of membrane fusion at the molecular level. Most of the early work will use model liposome systems. This is because biological membranes are complicated, heterogeneous matrices, and it is difficult to delineate the controlling molecular factors. However, there is good evidence that liposomes fuse by a similar mechanism, and that the knowledge gained form the model studies can be used to explain how fusion proteins work. Furthermore, a detailed understanding of liposome fusion is itself a clinically useful goal because liposomes are used as drug delivery vehicles. Currently, the stalk hypothesis is the most accepted, general mechanism for membrane fusion. However, it is hard to prove this mechanism because the transient fusion intermediates are difficult to observe and characterize. A close examination of the stalk mechanism suggests that molecules with specific topologies and polarities should be able to stabilize or destabilize the putative fusion intermediates and thus promote or inhibit fusion. The specific aims of this application are: 1. Test the recently hypothesized, extended conformation mechanism for membrane fusion by evaluating the fusion inhibition ability of a series of conformationally restricted polar lipids. 2. Prepare and evaluate fusion promoters that are rationally designed to facilitate the stalk fusion mechanism. Two types of fusion promoters will be explored, (i) hydrophobic hexadecane dendrons that fill and stabilize the stalk interstitial voids, and (ii) spherical, ionic dendrimers that stabilize the highly curved surfaces of the stalk fusion intermediates. An effective promoter will be viewed as supporting evidence for the stalk mechanism, whereas negative results will require the model to be re-evaluated. 3. Prepare a series of dendrimer-steroid and dendrimer-liposome conjugates and evaluate if they have potential applications in gene therapy and drug delivery. 4. Use the accumulated data to formulate an improved molecular mechanism for biological membrane fusion.

该项目的长期目标是发明促进或抑制生物膜融合的新材料。这项工作将为卫生和卫生科学带来实际和智力上的好处。从实际应用的角度来看，新型融合催化剂的开发将是杂交瘤研究、基因治疗和药物输送领域的一个可喜的技术进步；然而，融合抑制剂可以作为一种新的治疗药物用于一系列疾病领域，特别是机会性感染。启动子和抑制剂的设计将在分子水平上测试我们目前对膜融合的理解，这将是实质性的智力贡献。大多数早期工作将使用模型脂质体系统。这是因为生物膜是复杂的异质基质，很难描述控制分子因素。然而，有很好的证据表明脂质体通过类似的机制融合，并且从模型研究中获得的知识可以用来解释融合蛋白是如何工作的。此外，对脂质体融合的详细了解本身就是一个临床有用的目标，因为脂质体被用作药物递送载体。目前，茎说是最被接受的膜融合的一般机制。然而，由于瞬态聚变中间体难以观察和表征，因此很难证明这一机制。对茎机制的仔细研究表明，具有特定拓扑结构和极性的分子应该能够稳定或破坏假定的融合中间体，从而促进或抑制融合。该应用程序的具体目标是：1。通过评估一系列构象限制极性脂质的融合抑制能力来测试最近假设的膜融合的扩展构象机制。2. 制备和评价合理设计以促进茎融合机制的融合促进剂。将探索两种类型的融合促进剂，(i)疏水十六烷树突填充和稳定茎间隙空隙，以及（ii）球形，离子树突稳定茎融合中间体的高弯曲表面。有效的启动子将被视为支持梗机制的证据，而阴性结果将需要对模型进行重新评估。3. 制备一系列树状聚合物-类固醇和树状聚合物-脂质体缀合物，并评估它们在基因治疗和药物传递方面的潜在应用。4. 利用积累的数据，制定一个改进的生物膜融合的分子机制。