Loiseau P M, Maarouf M, Gayral P, Petek F
Biologie et Contrôle des Organismes Parasites, Université de Paris XI, Châtenay-Malabry, France.
Parasitol Res. 1993;79(5):397-401. doi: 10.1007/BF00931829.
Malate dehydrogenase (MDH) (E.C.1.1.1.37) activity was detected in the filaria Molinema dessetae at a level similar to those found in other filariae. In M. dessetae, the cytoplasmic form (c-MDH) predominated and the study was performed on partially purified fractions. The pH optimum for oxaloacetate reduction was 6.1, with maximal activity at 7811 nmol min-1 mg protein-1, but high concentrations of oxaloacetate inhibited MDH activity. The Km value for oxaloacetate was determined as 22 microM for M. dessetae c-MDH and 33 microM for mammalian c-MDH. Anthelmintic drugs were compared as potential inhibitors of filarial and mammalian c-MDH. Among the compounds evaluated, amocarzine showed a specific inhibitory effect on filarial c-MDH through only at high concentrations. Suramin alone showed an inhibitory effect at low concentrations (Ki = 1.15 microM) but without selective action towards filarial c-MDH. The suramin type of inhibition was found to be competitive. Suramin probably acts on both enzymes in the same manner. Nevertheless, M. dessetae c-MDH is proposed as a suitable enzyme assay model to screen MDH inhibitors as potential filaricides.
在丝状线虫莫氏丝状线虫中检测到苹果酸脱氢酶（MDH）（E.C.1.1.1.37）的活性，其水平与在其他丝状线虫中发现的水平相似。在莫氏丝状线虫中，细胞质形式（c-MDH）占主导地位，并且该研究是在部分纯化的组分上进行的。草酰乙酸还原的最适pH为6.1，最大活性为7811 nmol min-1 mg蛋白-1，但高浓度的草酰乙酸会抑制MDH活性。莫氏丝状线虫c-MDH的草酰乙酸Km值测定为22 microM，哺乳动物c-MDH的Km值为33 microM。比较了驱虫药作为丝状线虫和哺乳动物c-MDH的潜在抑制剂的效果。在所评估的化合物中，阿莫卡嗪仅在高浓度时对丝状线虫c-MDH表现出特异性抑制作用。单独的苏拉明在低浓度时（Ki = 1.15 microM）表现出抑制作用，但对丝状线虫c-MDH没有选择性作用。发现苏拉明的抑制类型是竞争性的。苏拉明可能以相同的方式作用于这两种酶。尽管如此，莫氏丝状线虫c-MDH被提议作为一种合适的酶测定模型，用于筛选作为潜在杀丝虫剂的MDH抑制剂。
