摘要
取产后两天内25℃保存的桑蚕卵为材料,精制酯酶A_4。将滞育卵中精制的酶液置5℃下冷藏,冷藏初期酶活性极低,大致在12~13日达最大值。以后迅速降低,体外保存的温度条件与酯酶A_4活性有关,较高的保存温度能促使酶活性峰提早出现:而低温保护能延缓酶的活化进程。酯酶A_4精制过程中,通过Sephadex G-25凝胶过滤,将大部分物质分段与酶分离排除,在5℃条件下,酶活性峰出现以前的任何时候加入排除分段物质,都可以停止酶的活性化,只有当重新除去所加的排除分段物质时,酶的活性化进程才得以继续。
The esterase A4 has been purified from diapause eggs of Bombyx mori 2 days after oviposition. This enzyme activity remained at low levels during the early period of chilling at 5℃ in vitro. It suddenly increased on the 12th day of chilling and reached its peak on the 13th day, then it was followed by a sudden fall. Incubation temperature in vitro had some bearing on the enzyme activation. Most parts were seperated from esterase A4 as void fraction through sephadex G-25 gel filtration. The esterase A4 activity elevation could be stopped under 5℃ by adding such kind of void fraction before the peak of enzyme showed. The esterase A4 activation could resume only when the void fraction was excluded.
关键词
蚕卵
酯酶A4
滞育发育
桑蚕
eggs
Bombyx mori L.
esterase A4
diapause development