Iwata Y, Pan Y, Yoshida T, Hanada H, Shigekawa M
Department of Molecular Physiology, National Cardiovascular Center Research Institute, Suita, Osaka, Japan.
FEBS Lett. 1998 Feb 20;423(2):173-7. doi: 10.1016/s0014-5793(98)00085-4.
Overlay and co-sedimentation assays using recombinant alpha1-syntrophin proteins revealed that two regions of alpha1-syntrophin, i.e. aa 274-315 and 449-505, contain high-affinity binding sites for F-actin (Kd 0.16-0.45 microM), although only a single high-affinity site (Kd 0.35 microM) was detected in the recombinant full-length syntrophin. We also found that actomyosin fractions prepared from both cardiac and skeletal muscle contain proteins recognized by anti-syntrophin antibody. These data suggest a novel role for syntrophin as an actin binding protein, which may be important for the function of the dystrophin-glycoprotein complex or for other cell functions. We also found that alpha1-syntrophin binds calmodulin at two distinct sites with high (Kd 15 nM) and low (Kd 0.3 microM) affinity.
使用重组α1-肌养蛋白进行覆盖和共沉降分析表明，α1-肌养蛋白的两个区域，即氨基酸274 - 315和449 - 505，含有与F-肌动蛋白的高亲和力结合位点（解离常数Kd为0.16 - 0.45微摩尔），尽管在重组全长肌养蛋白中仅检测到一个高亲和力位点（Kd为0.35微摩尔）。我们还发现，从心肌和骨骼肌制备的肌动球蛋白组分含有可被抗肌养蛋白抗体识别的蛋白质。这些数据表明肌养蛋白作为肌动蛋白结合蛋白具有新的作用，这可能对肌营养不良蛋白-糖蛋白复合物的功能或其他细胞功能很重要。我们还发现α1-肌养蛋白在两个不同位点以高亲和力（Kd为15纳摩尔）和低亲和力（Kd为0.3微摩尔）结合钙调蛋白。
