Yoshida H, Murachi T, Tsukahara I
Curr Eye Res. 1985 Sep;4(9):983-8. doi: 10.3109/02713689509000005.
The age-related changes of calpain II (high-Ca2+-requiring form of Ca2+-dependent cysteine proteinase; EC 3.4.22.17) and alpha-crystallin in the lens of hereditary cataract (Nakano; cac/cac) mouse were studied. Before the onset of the cataract formation, i.e., at the end of the 2nd week after birth, the calpain activity in Nakano mice was as high as that in the control ICR mice, but it decreased rapidly as the cataract progressed to completion during the 4th and the 12th week. Marked degradation of lens proteins ensued between the 2nd and the 4th weeks, and one of these proteins was identified, using monospecific antibodies, as B chain of alpha-crystallin. A chain of alpha-crystallin was not degraded in vivo, in contrast to its known susceptibility to calpain in vitro. The present data suggest that in Nakano mice, calpain may be involved in the onset or early stage of the cataract formation.
研究了遗传性白内障（中野；cac/cac）小鼠晶状体中钙蛋白酶II（高钙依赖性半胱氨酸蛋白酶的高钙需求形式；EC 3.4.22.17）和α-晶状体蛋白与年龄相关的变化。在白内障形成之前，即在出生后第2周结束时，中野小鼠的钙蛋白酶活性与对照ICR小鼠一样高，但随着白内障在第4周和第12周发展至完全形成，其活性迅速下降。在第2周和第4周之间，晶状体蛋白发生了明显降解，使用单特异性抗体鉴定出其中一种蛋白为α-晶状体蛋白的B链。与已知的α-晶状体蛋白A链在体外对钙蛋白酶的敏感性相反，其在体内未发生降解。目前的数据表明，在中野小鼠中，钙蛋白酶可能参与了白内障形成的起始或早期阶段。
