BIOPHYSICAL INVESTIGATIONS OF GAMMA-CRYSTALLINS

γ-晶状体蛋白的生物物理研究

• 批准号: 3465797
• 负责人: JAN WOLANCZYK
• 金额: $ 9.27万
• 依托单位: STATE UNIVERSITY OF NY,BINGHAMTON
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-08-01 至 1995-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3465797
• 关键词: acidity /alkalinity; biophysics; cataract; chemical structure function; cow; cryoscience; crystallins; infrared spectrometry; laser spectrometry; protein biosynthesis; thermostability

In excess of 50% of the population of the United States over 50 years of age has some form of cataract. Typical treatment for cataractous lenses involves their surgical removal followed by implantation of a fixed focus lens. In mammalian lenses, the core of the lens consists of a group of water soluble proteins termed gamma-crystallins. This family of proteins is monomeric with a molecular weight of approximately 20,000 daltons. There is a high degree of both sequence and structural homology present between the gamma-crystallins of different mammals and, for convenience, the gamma- crystallins from bovine calves are usually studied. The gamma-crystallins are named I - IV as a result of their elution profiles on a sulphopropyl column. There is selective synthesis of the individual gamma-crystallins with gamma-IV predominantly synthesized during foetal development. If a lens from a young mammal is cooled to 4oC, the lens becomes opaque. This opacity clears upon warming of the lens. This phenomenon is known as "cold cataract" and involves "cryoprecipitation at physiological concentrations. It is known that agents that increase the temperature at which these "cold cataracts" form, induce cataract formation in the whole lens. Conversely, agents that reduce the temperature of cold cataract formation can be used to clear chemically induced cataracts. It is therefore important to further characterize the biophysical behavior of these proteins. This study will compare and contrast the biophysical behavior of individual gamma-crystallins fractions. We will probe surface characteristics of these proteins in particular their interaction with water, investigate their thermal denaturation processes using both thermal analytical and spectroscopic techniques, and, investigate the enegetics involved during their cryoprecipitation.

超过 50% 的美国人口超过 50 年 年龄有某种形式的白内障。 白内障晶状体的典型治疗 包括手术切除它们，然后植入固定焦点 镜片。 在哺乳动物的晶状体中，晶状体的核心由一组水组成 可溶性蛋白质称为γ-晶状体蛋白。 这个蛋白质家族是 分子量约为 20,000 道尔顿的单体。 那里 之间存在高度的序列和结构同源性 不同哺乳动物的γ-晶状体蛋白，为了方便起见，γ- 通常研究来自小牛的晶状体蛋白。 γ-晶状体蛋白 由于其在磺丙基上的洗脱曲线而被命名为 I - IV 柱子。 选择性合成单个 γ-晶状体蛋白 γ-IV 主要在胎儿发育期间合成。 如果一个 年轻哺乳动物的晶状体冷却至 4°C 时，晶状体会变得不透明。 这 镜片变暖后，混浊就会消失。 这种现象被称为“冷 白内障”并涉及“生理浓度的冷沉淀”。 众所周知，可以提高这些“冷”温度的试剂 “白内障”的形成，诱发整个晶状体形成白内障。反之， 可以使用降低冷性白内障形成温度的药物 清除化学引起的白内障。 因此，进一步表征生物物理行为非常重要 这些蛋白质。 本研究将比较和对比生物物理 单个γ-晶状体蛋白组分的行为。 我们将探测表面 这些蛋白质的特征，特别是它们与 水，使用热研究它们的热变性过程 分析和光谱技术，并研究遗传学 参与他们的冷沉淀过程。