REGENERATION OF 11-CIS RETINAL IN THE RETINA

这项拨款申请的重点是11-顺式视网膜是如何在 脊椎动物的视网膜/色素上皮。如何解决的问题 这一过程是以两种不同但相互耦合的方式形成的。这个 第一个目标是确定11顺式视网膜的发病机制。 生物合成。这里非常重要的是要确定是否 全反式维甲酸异构化为11-顺式维甲酸 不管是不是酶介导的。第二个目标是确定 能量来自11-顺式维甲酸的生物合成。在黑暗中 适应的眼睛，超过75%的维甲酸可以以11顺式形式存在， 而在均衡时，只有0.1%是11顺形式的。形成了一种 等量的11-顺式和全反式维甲酸需要输入 大约4千卡/摩尔。 11-顺式维甲酸形成机制的问题将是 通过测定1)体内的立体特异性来探讨 异构化过程，2)全反式维甲酸异构化，3) 是否有任何证据表明维甲酸异构酶的存在 将被获得。如果发现一种酶的证据，这种酶将是 提纯和鉴定。无论是否存在异构酶， 必须找到生产11-顺式维甲酸的能源。我们的 这里的最终目标是确定11-顺式视网膜(O1)结合 蛋白质是否可以提供能量，或者是否依赖于ATP的机制可能 参与进来。 这里提到的研究可能对理解 某些形式的夜盲和视网膜色素变性的病因学。

This grant request is focused on how 11-cis retina is biosynthesized in the retina/pigmented epithelium of vertebrate animals. The question of how this process occurs is formulated in two separate but coupled ways. The first objective is to determine the mechanism of 11-cis retinal biosynthesis. Of great importance here is to determine whether the isomerization of an all trans retinoid to an 11-cis retinoid is enzyme-mediated or not. The second objective is to determine where the energy comes from for the biosynthesis of the 11-cis retinoids. In a dark adapted eye, greater than 75% of the retinoids can be in the 11-cis form, whereas at equilibrium, only 0.1% is in the 11-cis form. The formation of equal quantities of 11-cis and all-trans retinoids requires the input of approximately 4 kcal/mol. The question of the mechanism of 11-cis retinoid formation will be approached by determining 1) the in vivo stereospecificity of the isomerization process, 2) which all-trans retinoid is isomerized, and 3) whether any evidence for the material presence of a retinoid isomerase can be obtained. If evidence for an enzyme is found, the enzyme will be purified and characterized. Whether an isomerase enzyme exists or not, energy source for the production of 11-cis retinoid must be found. Our ultimate goal here is to determine whether the 11-cis retinal(o1) binding protein can provide the energy or whether an ATP-dependent mechanism might be involved. The research alluded to here could be of importance in understanding the etiology of certain forms of night blindness and retinitis pigmentosa.