1-methyladenosine ribohydrolase in the starfish ovary and its relation to oocyte maturation.
1-methyladenosine ribohydrolase in the starfish ovary and its relation to oocyte maturation.
复制标题
海星卵巢中的 1-甲基腺苷核糖水解酶及其与卵母细胞成熟的关系。
DOI：
10.1016/0014-4827(72)90522-8
复制
发表时间：
1972
影响因子：
3.7
通讯作者：
H. Kanatani
中科院分区：
文献类型：
--
作者：
H. Shirai;H. Kanatani
分离的卵母细胞的成熟诱导在孵育混合物的上清液中的卵巢片段，或其提取物，和含有1-甲基腺苷的海星，Patiria miniata，Asterias amurensis，Asterina pectinifera的海水。这种成熟诱导活性归因于通过卵巢组织中存在的酶的作用产生源自1-甲基腺苷的活性物质。经柱层析和薄层层析鉴定，活性物质为1-甲基腺嘌呤。这种酶似乎不是一种普通的腺苷核糖水解酶，而是一种新的特异性酶，称为1-甲基腺苷核糖水解酶，它将1-甲基腺苷分解为1-甲基腺嘌呤和核糖。在卵巢壁匀浆上清液中加入饱和度为0.45的硫酸铵，成功地沉淀出这种酶。发现该酶的最适pH为约7.5。其分子量估计为96 000，其等电点测定为pH 5.1。成熟的卵巢中含有成熟的卵母细胞表现出较高的1-甲基腺苷核糖水解酶的活性比年轻的卵巢，这表明该酶的活性是依赖于性腺的成熟度和酶是有关的卵母细胞的成熟和产卵的海星通过其能力，以产生1-甲基腺嘌呤。一种刺激性腺的激素肽，它诱导海星卵巢中1-甲基腺嘌呤的产生，对1-甲基腺苷核糖水解酶的活性没有影响。这表明性腺刺激物质在1-甲基腺嘌呤生物合成的早期阶段起作用。
Maturation of isolated oocytes was induced in the supernatant of an incubation mixture consisting of ovarian fragments, or their extract, and sea water containing 1-methyladenosine in the starfishes,Patiria miniata, Asterias amurensis, Asterina pectinifera. Such maturation-inducing activity was ascribed to the production of an active substance derived from 1-methyladenosine by the action of an enzyme present in ovarian tissue. With column chromatography and thin layer chromatography, the active substance was identified as 1-methyladenine. The enzyme does not seem to be an ordinary adenosine ribohydrolase, but a new specific enzyme to be called 1-methyladenosine ribohydrolase, which splits 1-methyladenosine into 1-methyladenine and ribose. This enzyme was successfully precipitated from the supernatant of ovarian wall homogenate by adding ammonium sulfate at 0.45 saturation. The optimal pH of the enzyme was found to be about 7.5. Its molecular weight was estimated as 96 000 and its isoelectric point was determined as pH 5.1. Ripe ovaries containing fullgrown oocytes showed higher 1-methyladenosine ribohydrolase activity than that of young ovaries, suggesting that the enzyme activity is dependent on the ripeness of the gonad and that the enzyme is related to both oocyte maturation and spawning in starfishes through its ability to produce 1-methyladenine. A gonad-stimulating hormonal peptide, which induces the production of 1-methyladenine in starfish ovaries, had no effect on the activity of 1-methyladenosine ribohydrolase. This suggests that the gonad-stimulating substance acts in some earlier stage of 1-methyladenine biosynthesis.