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.
Thomas
T J
TJ
Department of Medicine, University of Minnesota, Minneapolis 55455.
Messner
R P
RP
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