Esteves A, Joseph L, Paulino M, Ehrlich R
Sección Bioquímica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.
Int J Parasitol. 1997 Sep;27(9):1013-23. doi: 10.1016/s0020-7519(97)00071-4.
Four fatty acid binding proteins (FABPs) have been described in 4 parasitic platyhelminths: Schistosoma mansoni, Schistosoma japonicum, Fasciola hepatica and Echinococcus granulosus. FABPs form a multigenic family of cytosolic proteins widely distributed in metazoan tissues, the function of which is still poorly understood. These helminth proteins have recently received attention, since there are reports to indicate that S. mansoni and F. hepatica FABPs may be protective antigens. In addition, these proteins could play a major role in the parasites' life-cycles because platyhelminths are unable to synthesize de novo most of their lipids. We have undertaken phylogenetic and structural analyses of platyhelminth FABPs in an attempt to characterize features of biological relevance. Phylogenetically, these FABPs appear to be more closely related to those of vertebrate heart, mammary gland, muscle, retina, skin, brain and myelin, although no clear functional relationships were established between them. We describe several conserved motifs characteristic of specific groups of FABPs. Hydrophilicity, flexibility and accessibility analyses revealed several major putative epitopes for the E. granulosus FABP, EgDf1, that appear to be centred in loops of the EgDf1 3-dimensional structure modelled by molecular replacement.
在4种寄生扁形虫中已发现4种脂肪酸结合蛋白（FABP）：曼氏血吸虫、日本血吸虫、肝片吸虫和细粒棘球绦虫。FABP形成了一个多基因家族的胞质蛋白，广泛分布于后生动物组织中，其功能仍知之甚少。这些蠕虫蛋白最近受到了关注，因为有报道表明曼氏血吸虫和肝片吸虫的FABP可能是保护性抗原。此外，这些蛋白可能在寄生虫的生命周期中发挥重要作用，因为扁形虫无法从头合成它们的大多数脂质。我们对扁形虫FABP进行了系统发育和结构分析，试图表征具有生物学相关性的特征。在系统发育上，这些FABP似乎与脊椎动物的心脏、乳腺、肌肉、视网膜、皮肤、大脑和髓磷脂的FABP关系更密切，尽管它们之间没有明确的功能关系。我们描述了特定FABP组的几个保守基序。亲水性、柔韧性和可及性分析揭示了细粒棘球绦虫FABP（EgDf1）的几个主要推定表位，这些表位似乎集中在通过分子置换建模的EgDf1三维结构的环中。
