CELL FUSION IN MODEL AND BIOLOGICAL MEMBRANE SYSTEMS

这项提议的长期目标是阐明分子 膜融合参与胞吐过程的机制，以便 更好地了解和控制生物分泌现象 在正常和病理条件下。 为此，两种模型的膜融合平行研究 将进行分泌系统中的膜和生物膜的实验。 模型膜系统中的膜融合(脂泡、单层和 二价(或多价)阳离子诱导的双层膜)、温度 和渗透压梯度将被检查的情况下和 不含蛋白质或胆固醇的细胞膜。的效果 各种融合物质、生物分子(即花生四烯酸和 还将研究多胺)和磷酸钙对膜融合的影响。 膜融合将与自由能增加的程度相关 在膜表面由于离子的结合和结合而脱水 膜表面水对二价阳离子诱导的影响 在温度或渗透的情况下，由于膜的膨胀而发生融合 压力梯度导致膜融合，并由于膜表面 构象变化可能由钙结合蛋白介导。 为了将我们关于膜融合的知识应用于模型脂 膜系统与生物膜系统的相互作用与融合 在脂膜和生物膜之间(突触小泡， 嗜铬粒、红细胞泡等)将沿途检查 与上面总结的相同的行。 用于这些实验的方法将包括荧光和 发光融合分析、光散射测量、动态光 散射技术，用微天平测量重量，核磁共振， 电子显微镜、相差显微镜观察等 物理化学(表面化学等)确定以下内容的技术 膜的性质及其组成。

The long term goals of this proposal are to elucidate the molecular mechanism of membrane fusion involved in exocytotic processes, in order to have a better understanding and control of biological secretion phenomena under normal and pathological conditions. For this purpose, parallel studies of membrane fusion for both model membranes and biological membranes in secretory systems will be performed. Membrane fusion in model membrane systems (lipid vesicles, monolayer and bilayer membranes) induced by divalent (or polyvalent) cations, temperature and osmotic pressure gradients will be examined for the cases with and without proteins or cholesterol incorporated in the membranes. Effects of various fusogenic substances, biomolecules (i.e., arachidonic acid and polyamines) and calcium-phosphate on membrane fusion will also be studied. Membrane fusion will be correlated with the degree of free-energy increase in the membrane surface due to ion binding to and dehydration of bound water from the membrane surface for the case of divalent cation induced fusion, due to membrane expansion for the case of temperature or osmotic pressure gradient induced membrane fusion, and due to membrane surface conformational change possibly mediated by calcium binding proteins. In order to apply our knowledge about membrane fusion in model lipid membrane systems to biological membrane systems, the interaction and fusion between lipid membranes and biological membranes (synaptic vesicles, chromaffin granules, erythrocyte vesicles, etc.) will be examined along the same lines as summarized above. Methods to be used for these experiments will include fluorescence and luminescence fusion assays, light scattering measurements, dynamical light scattering techniques, weight measurements with a microbalance, NMR, electron microscopy, phase contrast microscopic observation, and other physico-chemical (surface chemistry, etc.) techniques to determine properties of the membranes and their constituents.