Institut für Allgemeine Botanik und Botanischer Garten, Universität Hamburg, Ohnhorststraße 18, D-2000, Hamburg 52, Federal Republic of Germany.
Planta. 1988 Mar;173(3):373-84. doi: 10.1007/BF00401024.
Cell-wall glycoproteins of the unicellular green alga Chlamydomonas reinhardii have been purified from LiCl extracts of intact cells by gel exclusion chromatography and preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Antibodies were raised against several polypeptide components isolated from the LiCl extracts. All these antibodies specifically reacted with the cell surface of formaldehyde-fixed cells. They showed cross-reactivity with the different antigens and were also reactive against some other polypeptides present in the LiCl extracts of intact wild-type cells as shown by double-diffusion assays and immunoblot analyses. These antigens were largely missing in LiCl extracts from the cell-wall-deficient mutant CW-15. The pattern of immunologically related cell-wall polypeptides of C. reinhardii varied during the vegetative cell cycle and was found to be also dependent on the growth conditions. Dot-immunobinding assays on chemically modified cell-wall glycoproteins demonstrated differences between the various antibodies with respect to their specificities. Differences were observed especially with respect to their reactivities against chemically deglycosylated cell-wall polypeptides. Chemical deglycosylation generally reduced the binding of the different antibodies indicating that all these antibodies recognize carbohydrate side chains. Only two of these antibody preparations, raised against cell-wall glycoproteins of relative molecular mass 35 and 150 kilodaltons, were found to be strongly reactive against deglycosylated cell-wall polypeptides. When these antibodies were saturated with cell-wall-derived glycopeptides in order to abolish the binding to carbohydrate side chains, they still recognized the same cell-wall polypeptides as did the untreated antibodies. These findings indicate that the cross-reactivity of the different cell-wall polypeptides with the antibodies is not exclusively the consequence of similar glycosylation patterns but is also the result of the presence of similar structures within the non-glycosylated stretches of the polypeptide backbones. Cell walls isolated from growing tobacco pollen tubes contained a single polypeptide component which showed crossreactivity with the antibodies to the cell-wall glycoproteins of C. reinhardii.
单细胞绿藻莱茵衣藻的细胞壁糖蛋白已从完整细胞的 LiCl 提取物中通过凝胶排阻色谱和制备性十二烷基硫酸钠-聚丙烯酰胺凝胶电泳进行了纯化。针对从 LiCl 提取物中分离出的几种多肽成分产生了抗体。所有这些抗体都特异性地与甲醛固定细胞的细胞表面反应。它们显示出与不同抗原的交叉反应性，并且在免疫印迹分析和双扩散测定中也对完整野生型细胞的 LiCl 提取物中存在的一些其他多肽反应。这些抗原在细胞壁缺陷型突变体 CW-15 的 LiCl 提取物中基本缺失。免疫相关的衣藻细胞壁多肽的模式在营养细胞周期中发生变化，并且还发现其依赖于生长条件。化学修饰的细胞壁糖蛋白的点免疫结合测定显示了各种抗体在特异性方面的差异。差异主要存在于它们对化学去糖基化细胞壁多肽的反应性方面。化学去糖基化通常会降低不同抗体的结合，表明所有这些抗体都识别碳水化合物侧链。只有两种针对相对分子质量为 35 和 150 千道尔顿的细胞壁糖蛋白的抗体制剂被发现对去糖基化细胞壁多肽具有强烈的反应性。当这些抗体与细胞壁衍生的糖肽饱和以消除与碳水化合物侧链的结合时，它们仍然识别未经处理的抗体所识别的相同细胞壁多肽。这些发现表明，不同细胞壁多肽与抗体的交叉反应性不仅是相似糖基化模式的结果，而且也是多肽骨架中非糖基化区域内存在相似结构的结果。从生长中的烟草花粉管中分离出的细胞壁包含一种与衣藻细胞壁糖蛋白的抗体发生交叉反应的单一多肽成分。
