First evidence on induced topological changes in supercoiled DNA by an aluminium D-aspartate complex

Ms., Bharathi and Jagannatha Rao, Kosagi Sharaf and Stein, Reuven (2003) First evidence on induced topological changes in supercoiled DNA by an aluminium D-aspartate complex. Journal of Biological and Inorganic Chemistry, 8. pp. 823-830.

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Abstract

Aluminium is a debatable and suspected etiological factor in neurodegenerative disorders. Aluminium –amino acid complexes also play an important role in the complex biology of the metal. Recent reports indicate the presence of D-aspartate and D-glutamate in aging brain, human breast tumors, core amyloid plaques and neurofibrillary tangles of Alzheimer’s brain. This stereoinversion from the L- to the D-enantiomer is enhanced by Al. Further, the observation that Al is localized in the chromatin region encouraged the present study of the interaction of Al–amino acid complexes with DNA. This study used circular dichroism of supercoiled DNA and showed that Al–D-Asp caused a native B-DNA to C-DNA conformational change, while Al–L-Asp, Al–L-Glu and Al–D-Glu did not alter the native B-DNA conformation. This differential DNA binding property of Al–amino acid complexes is assigned to the stereoisomerism and chirality of the complexes. Interestingly, polyamines like spermine further induced an asymmetric condensation of the ‘‘limit C-motif’’ induced by Al–D-Asp to a Y-DNA. The results were supported by computer modeling, gel studies and ethidium bromide binding. We also propose a mechanism of Al–D-Asp binding and its ability to modulate DNA topology.

Item Type:	Article
Uncontrolled Keywords:	Aluminium C-DNA DNA topology Racemization Spermine
Subjects:	500 Natural Sciences and Mathematics > 07 Life Sciences > 03 Biochemistry & Molecular Biology > 13 Molecular Biochemistry
Divisions:	Dept. of Biochemistry
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	04 Jul 2007 06:49
Last Modified:	04 Jun 2019 10:34
URI:	http://ir.cftri.res.in/id/eprint/1284

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