Basu H S, Marton L J
Department of Neurological Surgery, University of California, San Francisco 94143.
Biochem J. 1987 May 15;244(1):243-6. doi: 10.1042/bj2440243.
We studied the effects of spermine, two naturally-occurring pentamines isolated from the thermophile Thermus thermophilus and one synthetic pentamine on the aggregation and 'melting' temperature of calf-thymus DNA and on the B-to-Z transition of poly(dG-me5dC). All pentamines caused aggregation of DNA at much lower concentrations than that of spermine. Concentrations that increased the melting temperature of DNA and induced the B-to-Z transition in poly(dG-me5dC) were different for each pentamine, but were comparable with the concentration of spermine needed to cause these effects. Our results suggest that both the total charge and the distance separating the charge, which is a function of the length of the carbon chains between amino groups, are important for the induction of conformational changes in DNA. The biological role of pentamines in T. thermophilus appears to be related to their ability to promote DNA condensation at high temperature.
我们研究了精胺、从嗜热栖热菌中分离出的两种天然存在的五胺以及一种合成五胺对小牛胸腺DNA的聚集和“解链”温度以及聚(dG-me5dC)的B-Z转变的影响。所有五胺导致DNA聚集的浓度都比精胺低得多。每种五胺使DNA解链温度升高并诱导聚(dG-me5dC)发生B-Z转变的浓度各不相同,但与引起这些效应所需的精胺浓度相当。我们的结果表明,总电荷以及电荷之间的距离(其是氨基之间碳链长度的函数)对于诱导DNA构象变化都很重要。嗜热栖热菌中五胺的生物学作用似乎与其在高温下促进DNA凝聚的能力有关。