کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1316919 976491 2005 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Protecting or promoting effects of spermine on DNA strand breakage induced by iron or copper ions as a function of metal concentration
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی معدنی
پیش نمایش صفحه اول مقاله
Protecting or promoting effects of spermine on DNA strand breakage induced by iron or copper ions as a function of metal concentration
چکیده انگلیسی
Polyamines are ubiquitous polycations that participate in cellular processes such as growth, differentiation and cell death. Among the different functions ascribed to these organic cations, the polyamine spermine is known to protect DNA from the damage produced by reactive oxygen species (ROS) generated by different agents including copper ions. We have found that spermine exerts opposite effects on DNA strand breakage induced by Fenton reaction depending on metal concentration. Whereas at low concentration of the transition metals, 10 μM copper or 50 μM Fe(II), 1 mM spermine exerted a protective role, at metal concentrations higher than 25 μM copper or 100 μM Fe(II), spermine stimulated DNA strand breakage. The promotion of the damage induced by spermine was independent of DNA sequence but decreased by increasing the ionic concentration of the media or by the presence of metal-chelating agents. Moreover, spermine did not increase the oxidation of 2-deoxyribose by metal/H2O2 when DNA was substituted by 2-deoxyribose as a target for damage. Our results corroborate that spermine may protect DNA and 2-deoxyribose from the damage induced by ROS but also demonstrate that under certain conditions spermine may promote DNA strand breakage. The fact that this promoting effect of spermine on ROS-induced damage was observed only in the presence of DNA suggests that this polyamine under certain conditions may facilitate the interaction of copper and iron ions with DNA leading to the formation of ROS in close proximity to DNA.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Inorganic Biochemistry - Volume 99, Issue 10, October 2005, Pages 2074-2080
نویسندگان
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