Duschak V G, Goldemberg S H
Instituto de Investigaciones Bioquimicas Fundacion Campomar, Buenos Aires, Argentina.
Biochim Biophys Acta. 1987 Oct 9;910(1):21-6. doi: 10.1016/0167-4781(87)90090-x.
The polyamine content of the Escherichia coli polyamine-auxotrophic strain BGA 8 seemed to influence the effects of nalidixic acid, an antibiotic acting on subunit A of DNA gyrase. The growth rate was more affected under conditions of putrescine depletion and the inhibition could be partially relieved if the polycation was added back to the culture. DNA synthesis was likewise more sensitive to nalidixic acid in cultures grown without polyamine. The expression of some proteins characteristic of the heat-shock response, evoked by the antibiotic, showed a different persistence according to the presence or absence of polyamines. Novobiocin, acting on subunit B of gyrase, also promoted a differential effect depending on the polyamine content, but in this case putrescine-supplemented cells were more sensitive. The described findings suggest a role of polyamines in all the reactions carried out by gyrase, perhaps due to the influence of the polycations on the state of DNA aggregation.
大肠杆菌多胺营养缺陷型菌株BGA 8的多胺含量似乎会影响萘啶酸的作用效果，萘啶酸是一种作用于DNA促旋酶A亚基的抗生素。在腐胺耗尽的条件下，生长速率受到的影响更大，如果将这种聚阳离子重新添加到培养物中，抑制作用可部分缓解。在没有多胺的情况下培养的细菌中，DNA合成对萘啶酸同样更敏感。由抗生素引发的一些热休克反应特征性蛋白质的表达，根据多胺的存在与否表现出不同的持续性。新霉素作用于促旋酶的B亚基，也会根据多胺含量产生不同的影响，但在这种情况下，补充腐胺的细胞更敏感。上述研究结果表明，多胺在促旋酶进行的所有反应中都发挥作用，这可能是由于聚阳离子对DNA聚集状态的影响。
