Functional Characterization of a Guanylyl Cyclase-activating Protein from Vertebrate Rods
Functional Characterization of a Guanylyl Cyclase-activating Protein from Vertebrate Rods
复制标题
脊椎动物杆状鸟苷酸环化酶激活蛋白的功能表征
DOI：
--
复制
发表时间：
1996
影响因子：
4.8
通讯作者：
K. Koch
中科院分区：
文献类型：
--
作者：
S. Frins;W. Bönigk;F. Müller;R. Kellner;K. Koch
脊椎动物光感受器细胞中膜结合的鸟酰环化酶是视觉转导的关键酶之一。它对游离钙浓度（[Ca]）高度敏感。激活过程是协同的，由一种名为GCAP （guanyyl cyclase activation protein）的新型钙结合蛋白介导。我们从牛棒外段分离出GCAP，测定了蛋白水解获得的肽的氨基酸序列，并克隆了其基因。经sds -聚丙烯酰胺凝胶电泳测定，天然GCAP的ca结合形式的表观分子质量为20.5 kDa，无ca形式的表观分子质量为25 kDa。重组GCAP在大肠杆菌中功能表达。天然酰化GCAP对脊椎动物光感受器细胞中胍基环化酶的激活在100 nM free [Ca]时达到一半，Hill系数为2.5。重组非酰化GCAP的活化表现出较低的协同度（n = 2.0），半最大活化转移到261 nM free [Ca]。免疫细胞化学方法将GCAP定位于牛视网膜的视杆细胞和视锥细胞。
The membrane-bound guanylyl cyclase in vertebrate photoreceptor cells is one of the key enzymes in visual transduction. It is highly sensitive to the free calcium concentration ([Ca]). The activation process is cooperative and mediated by a novel calcium-binding protein named GCAP (guanylyl cyclase-activating protein). We isolated GCAP from bovine rod outer segments, determined amino acid sequences of proteolytically obtained peptides, and cloned its gene. The Ca-bound form of native GCAP has an apparent molecular mass of 20.5 kDa and the Ca-free form of 25 kDa as determined by SDS-polyacrylamide gel electrophoresis. Recombinant GCAP was functionally expressed in Escherichia coli. Activation of guanylyl cyclase in vertebrate photoreceptor cells by native acylated GCAP was half-maximal at 100 nM free [Ca] with a Hill coefficient of 2.5. Activation by recombinant nonacylated GCAP showed a lower degree of cooperativity (n = 2.0), and half-maximal activation was shifted to 261 nM free [Ca]. Immunocytochemically we localized GCAP only in rod and cone cells of a bovine retina.
视觉兴奋和恢复。
DOI：
--
发表时间：
1991
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Stryer,L
通讯作者：
Stryer,L
核苷酸类似物与杆外段鸟苷酸环化酶的相互作用。
影响因子：
2.9
作者：
Sitaramayya,A;Marala,RB;Hakki,S;Sharma,RK
通讯作者：
Sharma,RK