Bates P A
Department of Zoology, University of Glasgow, UK.
FEMS Microbiol Lett. 1993 Feb 15;107(1):53-8. doi: 10.1016/0378-1097(93)90353-4.
The parasitic protozoon Leishmania mexicana was examined for the presence of 3'-nucleotidase/nuclease using substrate SDS-PAGE. Two activities were detected: one with an apparent molecular mass of 40 kDa, and a doublet of 29/31 kDa. The two enzymes showed differences in their levels of expression in the two life-cycle stages of parasite examined: the 29/31 kDa doublet was detected at 60-fold higher levels in the pathogenic amastigote stage, but was also expressed by promastigotes, whereas the 40 kDa activity was only detected in promastigotes. Both were capable of hydrolysing a variety of substrates including 3'-AMP and poly(A). However, the 29/31 kDa form showed a broader, unique substrate specificity in that it was also capable of digesting double-stranded RNA and DNA.
利用底物SDS-PAGE检测寄生原生动物墨西哥利什曼原虫中3'-核苷酸酶/核酸酶的存在情况。检测到两种活性：一种表观分子量为40 kDa，另一种是29/31 kDa的双峰。在所检测的寄生虫的两个生命周期阶段，这两种酶的表达水平存在差异：在致病的无鞭毛体阶段检测到29/31 kDa双峰的水平比前鞭毛体阶段高60倍，但前鞭毛体也有表达，而40 kDa的活性仅在前鞭毛体中检测到。二者都能够水解多种底物，包括3'-AMP和聚腺苷酸。然而，29/31 kDa的形式表现出更广泛、独特的底物特异性，因为它还能够消化双链RNA和DNA。
