Kato Y, Iwase H, Hotta K
Arch Biochem Biophys. 1986 Feb 1;244(2):408-12. doi: 10.1016/0003-9861(86)90607-7.
Ovalbumin extracted from oviduct slices incubated with [35S]methionine or [2-3]mannose contained two biosynthetic intermediates, OE and OF (Y. Kato, H. Iwase, and K. Hotta, 1984, J. Biochem. (Tokyo) 95, 455-463). In the present study, these intermediates are further characterized. The 3H dpm/35S dpm ratio of OF labeled with both [35S]methionine and [3H]mannose was twice that or greater than that of OE. The tritium-labeled OF migrated more slowly than OE on sodium dodecyl sulfate-gel electrophoresis and had a molecular weight exceeding that of OE by about 1500. These findings, along with the fact that [3H]OF had sugar chains similar to those of [3H]OE, suggest that OF may possibly have two sugar chains in one molecule. For confirmation of this, the glycosylation sites of OF were examined. Peptic and tryptic glycopeptides were prepared from [2-3H]mannose-labeled OF and the other ovalbumin subfractions--OA, OC, OD, and OE--and then analyzed by high-performance liquid chromatography. The peptic glycopeptides prepared from [3H]OF contained glycopeptides in addition to those derived from the other subfractions although tryptic glycopeptides obtained from [3H]OF were similar to those from the other subfractions. This shows that the above hypothesis is valid.
从用[35S]甲硫氨酸或[2-3]甘露糖孵育的输卵管切片中提取的卵清蛋白含有两种生物合成中间体，OE和OF（Y. 加藤、H. 岩濑和K. 堀田，1984年，《生物化学杂志》（东京）95，455 - 463）。在本研究中，对这些中间体进行了进一步表征。用[35S]甲硫氨酸和[3H]甘露糖标记的OF的3H dpm/35S dpm比值是OE的两倍或更高。在十二烷基硫酸钠凝胶电泳中，氚标记的OF迁移速度比OE慢，其分子量比OE大约大1500。这些发现，连同[3H]OF具有与[3H]OE相似的糖链这一事实，表明OF可能在一个分子中含有两条糖链。为了证实这一点，对OF的糖基化位点进行了检测。从[2-3H]甘露糖标记的OF以及其他卵清蛋白亚组分——OA、OC、OD和OE——制备了胃蛋白酶和胰蛋白酶糖肽，然后通过高效液相色谱进行分析。从[3H]OF制备的胃蛋白酶糖肽除了含有来自其他亚组分的糖肽外，还含有其他糖肽，尽管从[3H]OF获得的胰蛋白酶糖肽与来自其他亚组分的相似。这表明上述假设是正确的。
