Nizami W A, Siddiqi A H, Yusufi A N
J Helminthol. 1975 Dec;49(4):281-7. doi: 10.1017/s0022149x00026286.
Alkaline phosphatases from different trematodes occupying the same habitat have identical pH otima but different levels of enzyme activities. Isoparorchis hypselobagri, from the fish Wallago attu, shows four to six times more enzyme activity than Fasciolopsis buski, Gastrodiscoides hominis and Echinostoma malayanum, from the pig Sus scrofa, and Fasciola gigantica, Gigantocotyle explanatum, Cotylophoron cotylophorum and Gastrothylax crumenifer, from the buffalo Bubalus bubalis. At least two peaks of activity at different levels of pH were obtained for each trematode examined. Both Gastrodiscoides hominis and Isoparorchis hypselobagri enzymes had three peaks of alkaline phosphatase activity. The optimum temperature for maximum enzyme activity was 40 degrees C, above which rapid inactivation occurred. At temperatures below 40 degrees C, the enzymes of fish and mammalian trematodes did not behave similarly; I. hypselobagri enzyme being active over a wider range of temperature (20 degrees-40 degrees C. Various concentrations of KCN and arsenate proportionately inhibited enzyme activity. NaF Did not significantly influence enzyme activity, while Mg++ and Co++ acted as activators. The extent of inhibition or activation of enzyme activity of different trematodes varied, probably due to species differences. Both inhibition and activation of I. hypselobagri enzyme was higher than in the case of other trematodes.
生活在同一栖息地的不同吸虫的碱性磷酸酶具有相同的最适pH，但酶活性水平不同。寄生于鱼类瓦氏黄颡鱼的高背异双盘吸虫，其酶活性比寄生于猪的布氏姜片吸虫、人腹盘吸虫和马来棘口吸虫，以及寄生于水牛的巨片形吸虫、扩展巨槽绦虫、杯殖杯殖吸虫和瘤胃腹袋吸虫高4至6倍。在所检测的每种吸虫中，均在不同pH水平获得了至少两个活性峰。人腹盘吸虫和高背异双盘吸虫的酶均有三个碱性磷酸酶活性峰。酶活性最高时的最适温度为40℃，高于此温度酶会迅速失活。在40℃以下的温度时，鱼类和哺乳动物吸虫的酶表现不同；高背异双盘吸虫的酶在更宽的温度范围（20℃-40℃）内具有活性。不同浓度的氰化钾和砷酸盐会相应地抑制酶活性。氟化钠对酶活性无显著影响，而镁离子和钴离子起激活剂作用。不同吸虫酶活性的抑制或激活程度各不相同，这可能是由于物种差异所致。高背异双盘吸虫酶的抑制和激活程度均高于其他吸虫。
