Staron K, Kowalska-Loth B, Czerwinski R M, Bandorowska J, Guberska J
Department of Biochemistry, Warsaw University, Poland.
Biochim Biophys Acta. 1991 Jan 17;1088(1):36-40. doi: 10.1016/0167-4781(91)90150-k.
A type I topoisomerase has been purified from nuclei of a slime mold Physarum polycephalum and its activity was tested during spherulation. The final preparation contained a single polypeptide of about 100 kDa. Basic properties of Physarum topoisomerase I (substrate specificity, ionic requirement, sensitivity to inhibitors) were similar to those of topoisomerases from higher eukaryotes. Specific features of Physarum enzyme were that it was rapidly inactivated at 45 degrees C and did not react with antibodies against human topoisomerase I. The activity of topoisomerase I in developed dormant spherules decreased approx. 2-fold, as compared with a 4-fold decrease of RNA and a 10-fold decrease of DNA synthesis. Basic properties of the enzyme remained unchanged during spherulation.
已从多头绒泡菌的细胞核中纯化出一种I型拓扑异构酶，并在成球过程中对其活性进行了测试。最终制剂包含一条约100 kDa的单一多肽。多头绒泡菌拓扑异构酶I的基本特性（底物特异性、离子需求、对抑制剂的敏感性）与高等真核生物的拓扑异构酶相似。多头绒泡菌酶的特殊之处在于它在45℃时迅速失活，并且不与抗人拓扑异构酶I的抗体发生反应。与RNA合成下降4倍和DNA合成下降10倍相比，发育成熟的休眠球体中拓扑异构酶I的活性下降了约2倍。在成球过程中，该酶的基本特性保持不变。
