Hyman C, Pfenninger K H
J Cell Biol. 1985 Sep;101(3):1153-60. doi: 10.1083/jcb.101.3.1153.
The focus of this study is a quantitative biochemical analysis of the calcium-dependent interactions of calmodulin with a nerve growth cone preparation from fetal rat brain (Pfenninger, K. H., L. Ellis, M. P. Johnson, L. B. Freidman, and S. Somlo, 1983, Cell 35:573-584). The presence of calmodulin as an integral component of this preparation is demonstrated, and quantitative binding studies are presented. The binding of 125I-calmodulin to nerve growth cone material is shown to be highly specific, calcium dependent, and saturable at nanomolar calmodulin concentrations. Additionally, the growth cones' binding components appear to be membrane proteins. The individual molecular mass species of growth cone proteins displaying calcium-dependent calmodulin binding are also detailed and presented in comparison with those of synaptosomes. This analysis reveals differences between the calmodulin binding proteins of the growth cone preparation and the synaptosome fraction, suggesting the presence in growth cones of a specialized set of components which may be involved in regulatory mechanisms controlling neuritic sprouting.
本研究的重点是对钙调蛋白与胎鼠脑的神经生长锥制剂之间的钙依赖性相互作用进行定量生化分析（Pfenninger, K. H., L. Ellis, M. P. Johnson, L. B. Freidman, and S. Somlo, 1983, 《细胞》35:573 - 584）。已证实钙调蛋白作为该制剂的一个组成部分存在，并进行了定量结合研究。结果表明，125I标记的钙调蛋白与神经生长锥物质的结合具有高度特异性、钙依赖性，且在纳摩尔浓度的钙调蛋白下可饱和。此外，生长锥的结合成分似乎是膜蛋白。还详细介绍了显示钙依赖性钙调蛋白结合的生长锥蛋白的各个分子量种类，并与突触体的分子量种类进行了比较。该分析揭示了生长锥制剂和突触体部分的钙调蛋白结合蛋白之间的差异，表明生长锥中存在一组可能参与控制神经突起萌发的调节机制的特殊成分。
