DIFFUSION OF MACROMOLECULES IN A MACROPARTICULATE SYSTEM

大颗粒系统中大分子的扩散

• 批准号: 3289899
• 负责人: GEORGE D PHILLIES
• 金额: $ 3.65万
• 依托单位: WORCESTER POLYTECHNIC INSTITUTE
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-07-01 至 1986-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3289899
• 关键词: diffusion; light scattering; macromolecule; particle; polymers

The diffusion of biopolymers is important in the dynamics of a living cell, the assembly of a virus and the purification of biomedical materials by column chromatography. Most systematic studies of biopolymer diffusion have been made on very dilute solutions. In contrast, macromolecule species in vivo may be present at concentrations which are high enough that physical interactions between neighboring macromolecules may affect their behaviors and solution properties. Quasi-elastic light scattering spectroscopy (QELSS) is broadly used to measure the diffusion coefficient of dilute macroparticle suspensions. Its application to more complex, concentrated solutions is obstructed by the difficulty in interpreting QELSS spectra in such cases. Our objectives in this proposal are twofold. First, develop methods for interpreting QELSS spectra of concentrated macromolecular mixtures and second, to develop a body of experience on the behavior of biopolymers diffusing through a macroparticulate background. Our major approach is based on the use of optical probes: materials labelled to scatter far more light than the background macroparticle suspension (chosen to be isorefractive with the solvent) through which the probes move. The use of optical probes greatly simplifies the interpretation of the spectrum. Optical labelling has been demonstrated experimentally, using polystyrene latex as a probe and water:poly-acrylic acid, water:polyethylene oxide, and water:serum albumin as background solutions. If the probe species is dilute, its scattering spectrum is determined by its tracer (single-particle) diffusion coefficient, the other solutes having only a secondary effect on the spectrum.

生物聚合物的扩散对于活细胞的动力学非常重要， 病毒的组装和生物医学材料的纯化 柱色谱法。 最系统的生物聚合物扩散研究 是在非常稀的溶液中制备的。 相比之下，高分子 体内的物种可能以足够高的浓度存在 相邻大分子之间的物理相互作用可能会影响它们的 行为和解决方案属性。 准弹性光散射 光谱学 (QELSS) 广泛用于测量扩散系数 稀释的大颗粒悬浮液。 它的应用更复杂， 浓缩溶液因难以解释而受阻 这种情况下的 QELSS 光谱。 我们在此提案中的目标是双重的。 首先，开发解释浓缩 QELSS 光谱的方法 第二，开发大分子混合物的经验体系 生物聚合物通过大颗粒背景扩散的行为。 我们的主要方法是基于光学探针的使用：材料 标记为比背景大粒子散射更多的光 悬浮液（选择与溶剂等折射），通过该悬浮液 探头移动。 光学探头的使用大大简化了 光谱的解释。 光学标记已被证明 实验中，使用聚苯乙烯乳胶作为探针和水：聚丙烯酸 酸、水：聚环氧乙烷和水：血清白蛋白作为背景 解决方案。 如果探针物质是稀的，则其散射光谱为 由其示踪剂（单粒子）扩散系数决定，其他 溶质对光谱仅具有次要影响。