Takano E, Ma H, Yang H Q, Maki M, Hatanaka M
Laboratory of Human Tumor Viruses, Kyoto University, Japan.
FEBS Lett. 1995 Mar 27;362(1):93-7. doi: 10.1016/0014-5793(95)00219-y.
Calpastatin molecule contains four repeated inhibition domains, each having highly conserved internal regions A, B and C. The synthetic oligopeptides of regions A and C had no calpain inhibition activity while region B oligopeptide showed weak inhibition activity. Real-time biomolecular interaction analysis using a BIAcore instrument revealed that the bacterially expressed calmodulin-like domain of the calpain large subunit (L-CaMLD) and that of the small subunit (S-CaMLD) interacted, in a Ca(2+)-dependent fashion, preferentially with the immobilized synthetic oligopeptide of region A and that of region C, respectively. Calmodulin showed no specific binding to these oligopeptides. The tripartite structure of the calpastatin functional domain may confer the specific interactions with the protease domain and the two CaMLDs of calpain.
钙蛋白酶抑制蛋白分子包含四个重复的抑制结构域，每个结构域都有高度保守的内部区域A、B和C。区域A和C的合成寡肽没有钙蛋白酶抑制活性，而区域B寡肽显示出较弱的抑制活性。使用BIAcore仪器进行的实时生物分子相互作用分析表明，钙蛋白酶大亚基的细菌表达的类钙调蛋白结构域（L-CaMLD）和小亚基的类钙调蛋白结构域（S-CaMLD）分别以钙依赖的方式优先与固定化的区域A和区域C的合成寡肽相互作用。钙调蛋白与这些寡肽没有特异性结合。钙蛋白酶抑制蛋白功能结构域的三方结构可能赋予其与钙蛋白酶的蛋白酶结构域和两个CaMLD的特异性相互作用。
