Wimmer M, Schmid B, Tag C, Hofer H W
Faculty of Medicine, Institute of Anatomy, University of Giessen, Germany.
Exp Parasitol. 1998 Feb;88(2):139-45. doi: 10.1006/expr.1998.4235.
Protein tyrosine phosphatases were analyzed in oocytes of Ascaris suum. Phosphatases dephosphorylating modified acidic lysozyme were present in high-molecular-weight form (M(r) > 600,000) and as a 50- to 55-kDa protein in the soluble fraction. The low-molecular-weight form of the phosphatase cross-reacted with an antiserum raised against human T-cell protein tyrosine phosphatase and was not distinguishable from the 50- to 55-kDa protein tyrosine phosphatase previously described in the muscular layer of the adult worms (B. Schmid et al. 1996, Molecular and Biochemical Parasitology 77, 183-192). The low-molecular-weight form was also present on immunoblots of high-molecular-weight protein tyrosine phosphatase preparations after denaturing electrophoresis. The same or a similar form of the tyrosine phosphatase was also found in detergent extracts from the pelletal fraction. In addition, another tyrosine phosphatase of 180 kDa molecular mass that dephosphorylated myelin basic protein was also found in extracts from the soluble compartment as well as in detergent extracts from the pelletal fraction. It showed no cross-reactivity with antisera raised against soluble mammalian phosphatases and was resistant to inhibition by vanadate. While the activities of the myelin basic protein-dephosphorylating protein phosphatase remained fairly constant during early development of the oocytes, the activity of the enzyme dephosphorylating modified lysozyme in the pelletal fraction decreased to less than 10% of the initial activity between days 3 and 28 of incubation. Immunocytochemical studies of unfertilized and developing Ascaris eggs revealed association of protein tyrosine kinase and protein tyrosine phosphatase with the egg shell, in addition to their presence in the neighborhood of mitochondria. The amount of enzyme changed with the stage of development. In the larval stage (21 days) protein tyrosine kinase had increased in the chitin layer of the shell and in the nuclei while the relative amount of tyrosine phosphatase decreased in accordance with the biochemical data.
对猪蛔虫卵母细胞中的蛋白酪氨酸磷酸酶进行了分析。使修饰酸性溶菌酶去磷酸化的磷酸酶以高分子量形式（M(r)>600,000）存在，并且以50至55kDa的蛋白质形式存在于可溶部分中。该磷酸酶的低分子量形式与针对人T细胞蛋白酪氨酸磷酸酶产生的抗血清发生交叉反应，并且与先前在成虫肌肉层中描述的50至55kDa蛋白酪氨酸磷酸酶没有区别（B.施密德等人，1996年，《分子与生化寄生虫学》77卷，183 - 192页）。在变性电泳后的高分子量蛋白酪氨酸磷酸酶制剂的免疫印迹上也存在低分子量形式。在来自沉淀部分的去污剂提取物中也发现了相同或相似形式的酪氨酸磷酸酶。此外，在可溶部分的提取物以及来自沉淀部分的去污剂提取物中还发现了另一种分子量为180kDa、使髓鞘碱性蛋白去磷酸化的酪氨酸磷酸酶。它与针对可溶性哺乳动物磷酸酶产生的抗血清没有交叉反应，并且对钒酸盐抑制具有抗性。虽然在卵母细胞早期发育过程中，使髓鞘碱性蛋白去磷酸化的蛋白磷酸酶的活性保持相当恒定，但在培养的第3天至第28天之间，沉淀部分中使修饰溶菌酶去磷酸化的酶的活性下降至初始活性的不到10%。对未受精和发育中的猪蛔虫卵的免疫细胞化学研究表明，除了存在于线粒体附近外，蛋白酪氨酸激酶和蛋白酪氨酸磷酸酶还与卵壳相关。酶的量随发育阶段而变化。在幼虫阶段（21天），壳的几丁质层和细胞核中的蛋白酪氨酸激酶增加，而酪氨酸磷酸酶的相对量根据生化数据减少。
