Sequence specificity in spermine-induced structural changes in CG-oligomers.
The role of spermine in inducing A-DNA conformation in deoxyoligonucleotides has been studied using CCGG and GGCC as model sequences. It has been found that while CCGG adopts an alternating B-DNA conformation in low salt solution at low temperature, addition of spermine to this medium induces a B --greater than A transition. In contrast, the A-DNA-like structure of GGCC in low salt solution at low temperature does not change under the influence of spermine. This suggests a sequence-dependent behaviour of spermine. Further these results suggest that the A-DNA conformation observed in the crystals of d(iCCGG) and d(GGCC)2 might have been due to the presence of spermine in the crystallization cocktail.
Molecular Biophysics Unit, Indian Institute of Science, Bangalore.
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K
Majumder
S K
SK
Brahmachari
D002942:Circular Dichroism; D009682:Magnetic Resonance Spectroscopy; D009690:Nucleic Acid Conformation / Q000187:drug effects; D009838:Oligodeoxyribonucleotides; D013096:Spermine / Q000494:pharmacology*; D013696:Temperature
D009838:Oligodeoxyribonucleotides; D013096:Spermine