Gbenle G O, Opperdoes F R, Van Roy J
Acta Trop. 1986 Dec;43(4):295-305.
We have characterized a 3'-nucleotidase activity of T. brucei. The enzyme has a pH optimum of 8.7, is inactivated by chelating agents and stimulated by divalent cations. It is inhibited by Zn2+, Mn2+, pyrophosphate and the trypanocidal drug suramin for which it has a Ki of 3 microM. From cell fractionation experiments it is concluded that the enzyme is located in the plasma membrane. Alkaline 3'-endoribonuclease is also located in the plasma membrane of T. brucei and this activity shares a great number of properties with the 3'-nucleotidase activity, including its sensitivity to suramin. The possibility that both 3'-nucleotidase and endonuclease activities are catalyzed by the same enzyme cannot be excluded.
我们已对布氏锥虫的一种3'-核苷酸酶活性进行了表征。该酶的最适pH为8.7，可被螯合剂灭活，并受二价阳离子刺激。它受到Zn2+、Mn2+、焦磷酸和杀锥虫药物苏拉明的抑制，其对苏拉明的抑制常数Ki为3 microM。从细胞分级分离实验得出结论，该酶位于质膜中。碱性3'-核糖核酸外切酶也位于布氏锥虫的质膜中，并且这种活性与3'-核苷酸酶活性具有许多共同特性，包括对苏拉明的敏感性。不能排除3'-核苷酸酶和核酸外切酶活性由同一种酶催化的可能性。
