Studies on the Stability of the Human Cone Visual Pigments †
Studies on the Stability of the Human Cone Visual Pigments †
复制标题
人锥体视觉色素稳定性的研究 †
DOI：
--
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发表时间：
2009
影响因子：
3.3
通讯作者：
K. Ridge
中科院分区：
文献类型：
--
作者：
E. Ramon;X. Mao;K. Ridge
脊椎动物的视网膜包含两种感光细胞，视杆细胞和视锥细胞，这两种细胞含有它们特有的视觉色素，分别负责暗视和明视视觉。在视锥感光细胞中，有三种颜色的色素：蓝色、绿色和红色，每种都有一个独特的吸收最大值。这项研究的目的是确定获得并以稳定形式分离这些色素的最佳条件，从而促进使用高分辨率方法进行结构研究。为此，我们首先在哺乳动物细胞中表达了三种人视锥视蛋白，重组后的11顺式视网膜、增溶、纯化的洗涤剂与视紫红质的稳定性进行了比较。由于与视紫红质相比，所有这三种色素的稳定性都大大降低，因此使用了定点突变来尝试设计绿色锥体色素的稳定性。这些突变引入了视紫红质中存在的一些结构基序和翻译后修饰位点，以及已被发现稳定视杆蛋白脱辅基蛋白的氨基酸替代。我们还通过改变增溶和纯化过程中使用的洗涤剂和洗涤剂/脂的组成来改变绿色锥体色素的疏水环境，并将它们与膜中的视网膜重组色素进行了比较。我们的结果表明，这些变化并没有显著改善人类锥体色素固有的不稳定性，在某些情况下，会导致稳定性和蛋白质聚集性的下降。我们的结论是，需要进一步的努力才能使人类锥体色素稳定在适合高分辨率结构研究的形式。
The retina of vertebrates contains two kinds of photoreceptor cells, rods and cones, which contain their specific visual pigments that are responsible for scotopic and photopic vision, respectively. In cone photoreceptor cells, there are three types of color pigments: blue, green and red, each with a distinctive absorption maximum. The goal of this investigation was to identify optimal conditions under which these pigments could be obtained and isolated in a stable form, thereby facilitating structural studies using high‐resolution approaches. For this purpose, all three human cone opsins were initially expressed in mammalian cells, reconstituted with 11‐cis retinal, detergent solubilized, purified and their stability compared with rod rhodopsin. As all three pigments showed dramatically reduced stability relative to rhodopsin, site‐directed mutagenesis was used in an attempt to engineer stability into the green cone pigment. The mutations introduced some structural motifs and sites of posttranslational modification present in rhodopsin, as well as amino acid substitutions that have been found to stabilize the rod opsin apo‐protein. We also modified the hydrophobic environment of the green cone pigment by varying the detergent and detergent/lipid composition used during solubilization and purification, and compared them with the retinal reconstituted pigment in membranes. Our results show that these changes do not significantly improve the inherent instability of the human cone pigments, and in some cases, lead to a decrease in stability and protein aggregation. We conclude that further efforts are required to stabilize the human cone pigments in a form suitable for high‐resolution structural studies.
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影响因子：
2.9
作者：
OPRIAN, DD;ASENJO, AB;PELLETIER, SL
通讯作者：
PELLETIER, SL
异源三聚体 G 蛋白 α 亚基中与受体刺激的鸟嘌呤核苷酸交换相关的构象变化：GTPgammaS 结合状态的 NMR 分析。
DOI：
10.1074/jbc.m509851200
发表时间：
2006
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Ridge,KevinD;Abdulaev,NajmoutinG;Zhang,Cheng;Ngo,Tony;Brabazon,DanielleM;Marino,JohnP
通讯作者：
Marino,JohnP
视紫红质中的单个氨基酸取代（赖氨酸 248----亮氨酸）可防止转导蛋白的激活。
DOI：
--
发表时间：
1988
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Franke,RR;Sakmar,TP;Oprian,DD;Khorana,HG
通讯作者：
Khorana,HG
影响因子：
--
作者：
Garwin,GG;Saari,JC
通讯作者：
Saari,JC