Nishihara T, Gerton G L, Hedrick J L
J Cell Biochem. 1983;22(4):235-44. doi: 10.1002/jcb.240220405.
To investigate the molecular basis of the observed morphological and biological characteristics of coelomic egg envelopes (CE), vitelline envelopes (VE), and fertilization envelopes (FE) of Xenopus laevis eggs, envelopes were radioiodinated under a variety of conditions: in situ, isolated and intact, or solubilized. The distribution of 125I in envelope components was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Each envelope type displayed unique profiles when iodinated in the intact state. A major constituent of VE, the 41,500 molecular weight component, was not labeled in the intact state, although the corresponding component of CE was heavily labeled. After dissociation of the envelope by guanidine-HCl or sodium dodecyl sulfate, all of the components could be radioiodinated. However, when the envelopes (VE and FE) were dissolved by heating and subsequently radioiodinated by lactoperoxidase, the resulting radioactivity profile was similar to that of the intact envelopes, suggesting that in the heat-dissolved envelope, the individual components retain similar structural relations as in the intact envelope. Quantitative but not qualitative differences were found between the inner and outer aspects of VE and FE. The significance of these findings is discussed in relation to what is known about the morphological, biological, and molecular properties of the envelopes.
为了研究非洲爪蟾卵的体腔卵膜（CE）、卵黄膜（VE）和受精膜（FE）所观察到的形态学和生物学特征的分子基础，在多种条件下对这些膜进行放射性碘化：原位、分离且完整状态或溶解状态。通过十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳分析125I在膜成分中的分布。每种膜类型在完整状态下碘化时都显示出独特的图谱。VE的一种主要成分，分子量为41,500的成分，在完整状态下未被标记，而CE的相应成分则被大量标记。在用盐酸胍或十二烷基硫酸钠使膜解离后，所有成分都可以进行放射性碘化。然而，当膜（VE和FE）通过加热溶解并随后用过氧化物酶进行放射性碘化时，所得到的放射性图谱与完整膜的相似，这表明在热溶解的膜中，各个成分保持着与完整膜中相似的结构关系。在VE和FE的内部和外部方面发现了定量而非定性的差异。结合关于这些膜的形态学、生物学和分子特性的已知信息，讨论了这些发现的意义。
