Rogalski A A, Bouck G B
J Cell Biol. 1980 Aug;86(2):424-35. doi: 10.1083/jcb.86.2.424.
Purified flagella from Euglena yield a unique high molecular weight glycoprotein when treated with low concentrations of nonionic detergents. This glycoprotein termed "xyloglycorien" cannot be extracted from other regions of the cell, although a minor component that coextracts with xyloglycorien does have a counterpart in deflagellated cell bodies. Xyloglycorien is tentatively identified with a flagellar surface fuzzy layer that appears in negatively stained membrane vesicles of untreated flagella but not in similar vesicles after Nonidet P-40 extraction. The localization of xyloglycorien is further confirmed to be membrane associated by reciprocal extraction experiments using 12.5 mM lithium diiodosalicylate (LIS), which does not appreciably extract xyloglycorien, visibly solubilize membranes, or remove the fuzzy layer. Rabbit antibodies directed against the two major flagellar glycoproteins (xyloglycorien and mastigonemes) to some extent cross react, which may in part be caused by the large percentage of xylose found by thin-layer chromatography (TLC) analysis to be characteristic of both antigens. However, adsorption of anti-xyloglycorien sera with intact mastigonemes produced antibodies responding only to xyloglycorien, and vice versa, indicating the nonidentity of the two antigens. Antibodies or fragments of these antibodies used in immunofluorescence assays demonstrated that xyloglycorien is confined to the flagellum and possibly the adjacent reservoir and gullet. Binding could not be detected on the cell surface. The sum of these experiments suggests that, in addition to mastigonemes, at least one major membrane glycoprotein in Euglena is restricted to the flagellar domain and is not inserted into the contiguous cell surface region.
用低浓度非离子去污剂处理眼虫的纯化鞭毛时，会产生一种独特的高分子量糖蛋白。这种被称为“木糖糖蛋白”的糖蛋白无法从细胞的其他区域提取出来，尽管与木糖糖蛋白共提取的一种次要成分在去鞭毛的细胞体中确实有对应物。木糖糖蛋白初步被认为与鞭毛表面的模糊层有关，该模糊层出现在未处理鞭毛的负染膜泡中，但在使用Nonidet P - 40提取后的类似膜泡中不存在。通过使用12.5 mM二碘水杨酸锂（LIS）的相互提取实验进一步证实了木糖糖蛋白的定位与膜相关，LIS不会明显提取木糖糖蛋白、明显溶解膜或去除模糊层。针对两种主要鞭毛糖蛋白（木糖糖蛋白和鞭毛茸）的兔抗体在一定程度上会发生交叉反应，这可能部分是由于薄层色谱（TLC）分析发现两种抗原都具有高比例的木糖。然而，用完整的鞭毛茸吸附抗木糖糖蛋白血清会产生仅对木糖糖蛋白有反应的抗体，反之亦然，这表明两种抗原并不相同。在免疫荧光测定中使用这些抗体或其片段表明，木糖糖蛋白局限于鞭毛以及可能相邻的贮蓄泡和胞咽。在细胞表面未检测到结合。这些实验的结果表明，除了鞭毛茸之外，眼虫中至少有一种主要的膜糖蛋白局限于鞭毛区域，不会插入相邻的细胞表面区域。
