非洲爪蟾两种卵化酶分子对卵黄膜作用机制的探讨

在分离纯化非洲爪蟾孵化酶时，得到了６０ＫＤ和４０ＫＤ两种分子，用卵化酶的特异性抗ＧＳＴ－ＵＶＳ．２抗体进行Ｗｅｓｔｅｒｎ杂交的结果证明二者均为孵化酶分子。６０ｋＤ分子很不稳定，在纯化过程中极易降解活性４０ＫＤ分子可能是由６０ＫＤ分子经过降解或自身降解丢失了两个ＣＵＢ重复区而形成的，而ＣＵＢ重复区很可能在对受精膜分子结构的修饰或改造中具有重要作用，在进一步验证其蛋白酶活性和生物活性时，发现二者几乎具

MECHANISM OF TWO HATCHING ENZYME MOLECULES ON VITELLINE ENVELOPE DURING THE HATCHING PROCESS OF XENOPUS LAEVIS

Two molecular forms of Xenopus hatching enzyme, 60kD and 40kD molecules, was obtained during preparation and purification. Both of them were verified as the hatching enzyme molecules, using anti GST UVS.2 antibody as the probe. 60kD molecule was digested or autodigested easily into 40kD molecule during purification. It was indicated that 40kD molecule was probably derived from 60kD molecule with its two CUB repeats lost, and the two CUB repeats may play an important role in recognizing and/or modifying of the molecular structure of vitelline envelope. When the proteolytic and VE solubilizing activities of 60kD and 40kD molecules were further verified, it was found that both of them had very high proteolytic and also VE solubilizing activities. Almost the same VE solubilizing activity of both of them may present us a possible mechanism in the solubilization of vitelline envelope in early embryos. Therefore, it can be concluded that 1) 60kD and 40kD molecules may co ordinates with each other in the solubilization of vitelline envelope and the inner jelly layer, and each plays a different role in the different time of hatching process; 2) the digestion or autodigestion of 60kD molecules into 40kD molecules is probably a natural behavior, not just resulted from manipulations.