IRON LOADING INTO FERRITIN

拟议研究的目的是了解铁是如何装载的 并与铁蛋白一起保存。 我们的假设是负载是 由铜蓝蛋白在保护铁蛋白免受影响的过程中完成 被铁氧化。 我们建议建立一个特定的协会 铜蓝蛋白和铁蛋白重链之间，刺激 铜蓝蛋白的亚铁氧化酶活性将铁放入铁蛋白中。 我们 提出铁通过以下途径转运到铁蛋白的核心： 通道中的四颗α螺旋束下起了大雨。 我们进一步认为铁 然后通过在周围形成羟基氧化铁，安全地储存在铁蛋白中 成核位点是谷氨酸，主要在轻链中 铁蛋白。 最后，我们建议添加磷酸盐来使 聚氢氧化铁的完整、稳定的末端。 许多 这些研究将包括重组体的定点突变 人铁蛋白重蛋白和轻蛋白的均聚物。 这些 蛋白质在氨基酸同源性方面非常相似 和三维结构，因此只需很少的氨基酸变化 旨在研究重物和轻物的不同特性 均聚物。 提议涉及以下性质的氨基酸 一种均聚物可以通过定点诱变来改变以测试 在另一种均聚物中建立该特性。 相反，我们可以改变提议参与的氨基酸 存在于一种均聚物中的特性转化为相应的 均聚物中的氨基酸不具有以下性质 有兴趣看看该财产是否因变更而废除。 这样我们就可以 获得正（添加属性）和负（添加属性） 删除属性）结果。 我们建议描述 铁蛋白与铜蓝蛋白的关联以及刺激 铜蓝蛋白的亚铁氧化酶活性，铁负载的性质 铁蛋白通道，以及铁的性质、重要性和作用 铁蛋白中的成核位点。 最后我们来研究一下效果 磷酸盐对铁蛋白铁核稳定性的影响。 现场定向 诱变将由计算机建模指导，使用已发表的 序列。

The objective of the proposed research is to learn how iron is loaded and stored with ferritin. Our hypothesis is that loading is accomplished by ceruloplasmin in a process that protects ferritin from oxidation by iron. We propose that there is a specific association between ceruloplasmin and the heavy chain of ferritin which stimulates the ferroxidse activity of ceruloplasmin to place iron into ferritin. We propose that iron is transported into the core of ferritin through a channel in the four a-helix bundle of heavy rain. we further that iron is then safely stored in ferritin by forming ferric oxhydroxides around nucleation sites which are glutamic acids, mostly in the light chain of ferritin. Finally, we propose that phosphate is added to make complete, stable, terminal ends of polyferrioxyhydroxide. Many of the studies will include site-directed mutagenesis of recombinant homoplymers of the heavy and light proteins of human ferritin. These proteins are very similar both with respect to amino acid homology and three-dimensional structure so very few amino acid changes need to be made to study the different properties of the heavy and light homopolymers. Amino acids proposed to be involved in property of one hompolymer an be changed by site-directed mutagenesis to test for the establishment of that property in the other homopolymer. Conversely, we can change amino acids proposed to be involved in a property which resides in one homopolymer into the corresponding amino acid in the homopolymer that does not have a property of interest to see if the property is abolished by the change. Thus we can obtain both positive (the addition of a property) and negative (the deletion of a property) results. We propose to characterize the association of ferritin with ceruloplasmin and the stimulation of the ferroxidase activity of ceruloplsmin, the nature of the iron loading channel in ferritin, and the nature, importance and role of iron neculeation sites in ferritin. Finally, we will study the effect of phosphate on the stability of the iron core in ferritin. Site-directed mutagenesis will be guided by computer modeling using the published sequences.