Noel F, Pardon R S
Departamento de Farmacologia Basica e Clinica, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Brazil.
Life Sci. 1989;44(22):1677-83. doi: 10.1016/0024-3205(89)90484-0.
Vanadate inhibitory effects on Na+, K+-ATPases from carcass of Schistosoma mansoni and from lamb kidney outer medulla were compared in the presence of various concentrations of Na+, K+ and Mg2+. Depending on the ionic conditions, the schistosomal Na+, K+-ATPase was 2.4- to 175-fold less sensitive to vanadate than the lamb kidney enzyme. In 100 mM Na+, 3 mM K+ and 3 mM Mg2+, schistosomal Na+, K+-ATPase was surprisingly resistant to vanadate (I50 = 944 microM). The difference in vanadate sensitivity between schistosomal and lamb Na+, K+-ATPases may be due to a species difference in the efficacy of Na+, K+ and Mg2+ in promoting conformational changes between E1 and E2 forms of the enzyme.
在存在不同浓度的Na⁺、K⁺和Mg²⁺的情况下，比较了钒酸盐对曼氏血吸虫虫体和羔羊肾外髓质中Na⁺, K⁺-ATP酶的抑制作用。根据离子条件，血吸虫的Na⁺, K⁺-ATP酶对钒酸盐的敏感性比羔羊肾酶低2.4至175倍。在100 mM Na⁺、3 mM K⁺和3 mM Mg²⁺条件下，血吸虫的Na⁺, K⁺-ATP酶对钒酸盐具有惊人的抗性（半数抑制浓度I50 = 944 microM）。血吸虫和羔羊的Na⁺, K⁺-ATP酶对钒酸盐敏感性的差异可能是由于Na⁺、K⁺和Mg²⁺在促进酶的E1和E2形式之间构象变化的功效上存在种属差异。
