Structural specificity of polyamines in left-handed Z-DNA formation. Immunological and spectroscopic studies.
Natural polyamines putrescine, spermidine and spermine are ubiquitous cellular components. Recent studies showed that these compounds are capable of provoking a conformational transition in poly(dG-m5dC).poly(dG-m5dC) from its usual right-handed B-DNA form to a left-handed Z-DNA form at physiologically relevant cationic concentrations. We studied the efficacy of spermidine, six homologs of spermidine (H2N(CH2)nNH(CH2)3NH2, where n = 2 to 8 (n = 4 for spermidine)) and diethylene triamine to provoke the B-DNA to Z-DNA transition of poly(dG-m5dC).poly(dG-m5dC) using a monoclonal anti-Z-DNA antibody and spectroscopic techniques. The concentration of spermidine at the midpoint of B-DNA to Z-DNA transition was 30 +/- 1 microM. Chemical structural effects were significant when the spermidine homologs were used to induce the transition. The midpoint concentration increased as the number of -CH2 groups varied in relation to that of spermidine. We interpret these structural effects on the basis of molecular models of the interaction of polyamines with polynucleotides.
Department of Medicine, University of Minnesota, Minneapolis 55455.
T J
TJ
Thomas
R P
RP
Messner
D004247:DNA / Q000187:drug effects*; D009690:Nucleic Acid Conformation / Q000187:drug effects*; D011073:Polyamines / Q000494:pharmacology*; D013095:Spermidine / Q000494:pharmacology
D011073:Polyamines; C005391:diethylenetriamine; D004247:DNA; D013095:Spermidine