REGULATION OF PROTEIN PHOSPHORYLATION IN THE EYE

眼睛中蛋白质磷酸化的调节

• 批准号: 3259821
• 负责人: JAMES A NATHANSON
• 金额: $ 14.09万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-12-01 至 1992-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3259821
• 关键词: beta adrenergic agent; chromatography; cow; crystallins; gel electrophoresis; histochemistry /cytochemistry; homeostasis; lens proteins; phosphorylation; prostaglandins; scintillation counter; uvea ciliary body

In the course of aging and cataract formation, loss of lens transparency is associated with aggregation of structural lens proteins (crystallins) and increased light scattering. Many post- translational changes have been observed in both human and bovine proteins of aging and cataractous lenses. They include phosphorylation, oxidation of tryptophan, oxidation of methionine, selective degradation of polypeptide chains, disulfide bonding (protein-protein, or mixed disulfide) and non-enzymatic glycosylation. However, it is not known whether these modifications induce protein conformational change and precede protein aggregation and insolubilization. In this proposal, physicochemical measurements (UV-VIS absorption, circular dichroism, fluorescence and laser light scattering) will be employed, to observe (1) whether protein conformations (including secondary and tertiary structures, microenvironments of aromatic amino acids and sulfhydryl groups) have changed as a result of post-translational modifications, and if they do (2) whether conformationally altered lens proteins from aging and cataractous lenses give greater scattering and (3) whether these proteins become more vulnerable to exogeneous stresses (such as UV irradiation and hydrogen peroxide), (4) whether the change in protein conformation has facilitated protein aggregation and insolubilization, and finally (5) whether enzyme phosphofructokinase also undergoes similar conformational and post-translational changes as occurring in crystallins. The significance of these post-translational changes in lens protein conformation is that its may increase light scattering either through a decreased particle mobility, or through increased protein aggregation and isolubilization. The long-term objective of this proposal is to correlate post-translationally conformational changes to changes in light scattering observed both in protein solutions and in intact lenses in vitro.

在衰老和白内障的过程中，镜头的丧失 透明度与结构晶状体的聚集有关 蛋白质（结晶蛋白）并增加光散射。 许多职位 在人类和 老化和白内科镜头的牛蛋白。 它们包括 磷酸化，色氨酸的氧化，蛋氨酸的氧化，氧化， 多肽链的选择性降解，二硫键 （蛋白质 - 蛋白质或混合二硫化物）和非酶 糖基化。 但是，尚不知道这些是否 修饰会诱导蛋白质构象变化并在 蛋白质聚集和不溶液化。 在此提案中， 物理化学测量（UV-VIS吸收，圆形 二分色，荧光和激光散射）将是 使用，观察（1）是否蛋白质构象（包括 二级和第三级结构，芳香族的微环境 由于 翻译后修改，如果他们这样做（2）是否 衰老和白内障的构象改变的晶状体蛋白 镜片给出更大的散射，（3）这些蛋白是否是否 变得更容易受到外生压力的影响（例如紫外线 辐照和过氧化氢），（4） 蛋白质构象有促进蛋白质聚集和 不溶化，最后（5）是否酶 磷酸果糖激酶也经历了类似的构象和 在结晶蛋白中发生的翻译后变化。 这些镜头上翻译后变化的意义 蛋白质构象可能会增加光散射 通过减小的粒子迁移率或通过增加 蛋白质聚集和分离化。 长期目标 该提议的是将后构构相关联 在蛋白质中观察到的光散射变化的变化 溶液和完整的透镜体外。