Similarities and dissimilarities between calmodulin and a Chlamydomonas flagellar protein.
Similarities and dissimilarities between calmodulin and a Chlamydomonas flagellar protein.
复制标题
钙调蛋白和衣藻鞭毛蛋白之间的相似点和不同点。
DOI：
10.1073/pnas.77.8.4779
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发表时间：
1980
影响因子：
11.1
通讯作者：
Watterson,DM
中科院分区：
文献类型：
--
作者：
VanEldik,LJ;Piperno,G;Watterson,DM
一种类似于脊椎动物钙调蛋白和肌钙蛋白C的蛋白质已通过使用钙调蛋白纯化方案从衣原体鞭毛中分离出来，该方案包括在吩噻嗪-琼脂糖缀合物上的基于钙依赖性亲和力的吸附层析。鞭毛蛋白类似于钙调素从反相柱洗脱，有一个类似的钙调素的肽图，并竞争与脊椎动物钙调素在放射免疫测定中使用抗血清对脊椎动物钙调素。然而，这种鞭毛蛋白不激活磷酸二酯酶，缺乏N ε-三甲基赖氨酸，并且具有比脊椎动物钙调素高约0.3 pH单位的等电点。当在各种条件下通过聚丙烯酰胺凝胶电泳分析时，衣原体蛋白在脊椎动物钙调素和兔骨骼肌肌钙蛋白C之间迁移，并且没有表现出大的钙依赖性迁移率变化。这种钙调素样蛋白被确定为约200个35 S标记的衣原体鞭毛通过二维凝胶电泳解决的组件之一。这些研究表明，钙调素和结构和功能同源的蛋白质存在于同一细胞中。这些研究还表明，谨慎是必要的：（i）在确定蛋白质作为钙调素，（ii）在使用吩噻嗪或抗血清针对脊椎动物钙调素作为钙调素的特异性探针，和（iii）在生物系统中，钙调素被取代的同源钙调素样蛋白的实验的解释。
A protein that resembles vertebrate calmodulins and troponin C has been isolated from Chlamydomonas flagella by using a calmodulin purification protocol that included calcium-dependent affinity-based adsorption chromatography on phenothiazine-Sepharose conjugates. The flagellar protein resembled calmodulin in elution from reverse-phase columns, had a peptide map similar to that of calmodulin, and competed with vertebrate calmodulin in a radioimmunoassay using antisera against vertebrate calmodulin. However, this flagellar protein did not activate phosphodiesterase, lacked N epsilon-trimethyllysine, and had an isoelectric point approximately 0.3 pH unit higher than that of vertebrate calmodulin. When analyzed by polyacrylamide gel electrophoresis under various conditions, the Chlamydomonas protein migrated between vertebrate calmodulins and rabbit skeletal muscle troponin C and did not manifest a large calcium-dependent mobility shift. This calmodulin-like protein was identified as one of the approximately 200 35S-labeled components in Chlamydomonas flagella resolved by two-dimensional gel electrophoresis. These studies indicate that calmodulin and a structurally and functionally homologous protein are present in the same cell. These studies also demonstrate that caution is necessary: (i) in identifying a protein as a calmodulin, (ii) in using phenothiazines or antisera directed against vertebrate calmodulins as specific probes for calmodulin, and (iii) in the interpretation of experiments on biological systems in which calmodulin is substituted for the homologous calmodulin-like protein.