Plant Research Group, Department of Biology, MRC 306, Rensselaer Polytechnic Institute, 12180-3590, Troy, NY, USA.
Planta. 1990 Sep;180(3):361-71. doi: 10.1007/BF01160391.
Transmission electron microscopy and immunocytological labeling were used to localize the 32-kilodalton (kDa) protein (DI polypeptide) of photosystem II in different cell types of the cyanobionts within leaf cavities ofAzolla caroliniana Willd. The 32-kDa protein binds the secondary electron acceptor QB, and is highly conserved between plants and cyanobacteria. Three antisera, specific for different epitopes of the 32-kDa protein, were used as primary antibodies. Immunologically recognizable 32-kDa protein was localized on membranes ofAzolla chloroplasts, vegetative cyanobacterial cells, akinetes, and heterocysts that were at all stages of the differentiation process. The 32-kDa protein was not detected in nonphotosynthetic endosymbiotic bacteria found within leaf cavities. The amount of the 32-kDa protein observed in different cyanobacterial cell types was dependent upon the primary antiserum used and membrane orientation within a cell with respect to the plane of sectioning. Therefore, although 32-kDa protein was present in all three cyanobacterial cell types and clear trends in labeling patterns could be elucidated, it was not possible to quantitate the amounts of protein with respect to either cell type or leaf-cavity age.
利用透射电子显微镜和免疫细胞化学标记技术，对满江红叶腔内生蓝藻中不同细胞类型的光合系统 II 的 32kDa 蛋白（DI 多肽）进行了定位。该 32kDa 蛋白结合了次级电子受体 QB，在植物和蓝藻之间高度保守。三种抗血清，针对 32kDa 蛋白的不同表位，被用作一抗。在满江红叶绿体、营养性蓝藻细胞、静息孢子和异形胞的膜上，都检测到了具有免疫识别能力的 32kDa 蛋白，这些细胞处于分化过程的各个阶段。在叶腔中发现的非光合共生细菌中，未检测到 32kDa 蛋白。在不同的蓝藻细胞类型中观察到的 32kDa 蛋白的量取决于所用的一抗血清和细胞内膜相对于切片平面的方向。因此，尽管 32kDa 蛋白存在于所有三种蓝藻细胞类型中，并且可以清楚地阐明标记模式的趋势，但无法对蛋白的量进行定量，无论是相对于细胞类型还是叶腔年龄。
