PROTEINS OF NORMAL AND CATARACTOUS LENSES

我们的目标是确定氧化与 人类老年性白内障的形成及晶状体内条件的确定 这可能会促进氧化。重点将放在调查 晶状体蛋白的氧化，特别是晶状体蛋白的氨基酸残基 半胱氨酸、蛋氨酸和酪氨酸。氧化的晶状体蛋白类似于 已被发现存在于人类老年性白内障中的 通过使用X-射线、过氧化氢等方法在动物晶状体中生产 和高压氧。晶状体交联化的可能机制 晶体蛋白彼此之间以及与膜蛋白之间的关系将被研究 X射线中与膜形成二硫键交联物的晶体蛋白 白内障将被确认。人类形成机制的线索 核性白内障可能来自高压氧研究，两者都 在体内和体外。 不同的层析、电泳、氨基酸分析技术， 将使用光谱学、免疫化学和电子显微镜。 将使用银染技术来调查渗漏 晶体蛋白从X光晶体进入房水。多肽图谱将 对晶状体膜多肽MP22和MP26进行了比较 X光白内障。巯基在晶状体中作用的研究 人类和动物晶状体的膜将通过使用 结合SDA-PAGE的荧光和放射性巯基探针。 谷胱甘肽氧化还原循环在保护晶状体免受损伤中的作用 将详细研究氧化损伤，特别是在特定情况下 晶状体的各个区域。谷胱甘肽可能参与牙周炎的修复 晶状体氧化膜与正常膜通透性的恢复 将在培养的晶状体中进行研究，在用一种抑制剂处理后 谷胱甘肽还原酶和过氧化氢。放射性甘氨酸和谷氨酸将 用来测定培养晶状体上皮细胞GSH的转换率 细胞。将采用分离前后部的方法 为了研究H_2O_2对晶状体表面的解毒作用 这两个地区。老化对晶状体功能的影响 解毒过氧化氢将在人类晶状体和培养的兔晶状体中进行检测 上皮细胞。

Our objective is to determine the relationship of oxidation to the formation of human senile cataract and to define conditions in the lens which may promote oxidation. Emphasis will be placed on investigating the oxidation of lens proteins, particularly the amino acid residues of cysteine, methionine and tyrosine. Oxidized lens proteins similar to those which have been found to be present in human senile cataract will be produced in animal lenses by methods involving use of X-irradiation, H2O2 and hyperbaric oxygen. Possible mechanisms for the crosslinking of lens crystallins with each other and with membrane proteins will be examined and the crystallins which form disulfide crosslinks with membranes in X-ray cataract will be identified. Clues to the mechanism of formation of human nuclear cataract may be obtained from studies with hyperbaric oxygen both in vivo and in vitro. Diverse techniques of chromatography, electrophoresis, amino acid analysis, spectroscopy, immunochemistry and electron microscopy will be employed. Silver staining techniques will be used to investigate the leakage of crystallins from X-rayed lenses into aqueous humor. Peptide mapping will be carried out to compare the lens membrane polypeptides MP22 and MP26 in X-ray cataract. Investigations of the role of sulfhydryl groups in lens membranes of human and animal lenses will be aided by the use of fluorescent and radioactive sulfhydryl probes in conjunction with SDA-PAGE. The role of the glutathione redox cycle in defending the lens against oxidative damage will be examined in detail, particularly in specific regions of the lens. The possible involvement of GSH in the repair of oxidized lens membranes and restoration of normal membrane permeability will be studied in cultured lenses following treatment with an inhibitor of glutathione reductase and H2O2. Radioactive glycine and glutamic acid will be used to measure the turnover rate of GSH in cultured lens epithelial cells. Methods will be employed to isolate the anterior and posterior surfaces of the lens in order to investigate the detoxification of H2O2 in the two regions. The effect of aging on the ability of the lens to detoxify H2O2 will be examined in human lenses and in cultured rabbit lens epithelial cells.