Bahr V, Stierhof Y D, Ilg T, Demar M, Quinten M, Overath P
Max-Planck-Institut für Biologie, Tübingen, Germany.
Mol Biochem Parasitol. 1993 Mar;58(1):107-21. doi: 10.1016/0166-6851(93)90095-f.
The abundant surface glycoconjugate of Leishmania promastigotes, lipophosphoglycan (LPG), forms a blue-colored complex (lambda max = 649 nm) with the cationic dye Stains-all, which can be quantitated densitometrically on polyacrylamide gels of cell lysates. Promastigotes of Leishmania mexicana, Leishmania major and Leishmania donovani yield values of 1-3 x 10(6) LPG molecules cell-1. In amastigotes the LPG content is down-regulated below the detection limit (< 10(3) molecules cell-1) in L. mexicana and L. donovani, but remains significant in L. major (2 x 10(3) molecules cell-1). In the case of L. mexicana, these results are supported by immunological studies. Using several monoclonal and polyclonal antibodies, LPG is undetectable by immunoblotting in lysates of either amastigotes or infected macrophages and the amastigote surface is devoid of LPG as judged by immunofluorescence and immunoelectron microscopy. Immunoblotting experiments demonstrate that amastigotes synthesize hydrophilic high-molecular weight compounds which stain blue with Stains-all and cross-react with the monoclonal and polyvalent antibodies suggesting the presence of similar phosphoglycan structures as in LPG. The high-molecular weight phosphoglycan appears to be located in the lumen of the flagellar pocket of mouse lesion amastigotes and may be secreted from there into the lumen of the parasitophorous vacuole of parasitized macrophages. In L. mexicana promastigotes the surface protease gp63 is amphiphilic and comprises about 1% of the cellular proteins. In contrast, in amastigotes gp63-related proteins are predominantly hydrophilic; they amount to only about 0.1% of the cellular proteins and are mainly located in the lumen of the extended lysosomes (megasomes) characteristic for this species.
利什曼原虫前鞭毛体丰富的表面糖缀合物——脂磷壁酸聚糖（LPG），与阳离子染料全染剂形成蓝色复合物（最大吸收波长=649nm），该复合物可在细胞裂解物的聚丙烯酰胺凝胶上进行光密度定量分析。墨西哥利什曼原虫、硕大利什曼原虫和杜氏利什曼原虫的前鞭毛体产生的LPG分子数为1 - 3×10⁶个/细胞。在无鞭毛体中，墨西哥利什曼原虫和杜氏利什曼原虫的LPG含量下调至检测限以下（<10³个分子/细胞），但在硕大利什曼原虫中仍显著（2×10³个分子/细胞）。就墨西哥利什曼原虫而言，这些结果得到了免疫学研究的支持。使用多种单克隆和多克隆抗体，通过免疫印迹法在无鞭毛体或感染巨噬细胞的裂解物中均检测不到LPG，并且通过免疫荧光和免疫电子显微镜判断，无鞭毛体表面没有LPG。免疫印迹实验表明，无鞭毛体合成亲水性高分子量化合物，这些化合物用全染剂染成蓝色，并与单克隆和多价抗体发生交叉反应，表明存在与LPG中类似的磷酸聚糖结构。高分子量磷酸聚糖似乎位于小鼠病变无鞭毛体鞭毛袋的腔内，并可能从那里分泌到被寄生巨噬细胞的寄生泡腔内。在墨西哥利什曼原虫前鞭毛体中，表面蛋白酶gp63是两亲性的，约占细胞蛋白的1%。相比之下，在无鞭毛体中，gp63相关蛋白主要是亲水性的；它们仅占细胞蛋白的约0.1%，并且主要位于该物种特有的延伸溶酶体（巨大体）的腔内。
