Interaction between natural polyamines and synthetic deoxyoligonucleotides: an NMR study.

NIEMEVZ, F.; BULDAIN, G.Y.; DE CANDIA, A. AND FERNÁNDEZ, C.O.

Bariloche. Rio Negro. Argentina

Congreso; XXXII Reunión Anual de la Sociedad Argentina de Biofísica; 2003

Putrescine, spermidine and spermine are natural polyamines distributed in living organisms. The intracellular concentration ofpolyamines has been shown to influence cell growth andcarcinogenesis. The structural rationale for the physiological effects of polyamines has relied in the understanding of the polyaminenucleic acid interactions. Nuclear Magnetic Resonance (NMR)spectroscopy has provided valuable insights into tRNA-polymine interaction, giving support and enhancing structure-based drug design. In this work we extended our studies to explore the interaction between natural polyamines and synthetic deoxyoligonucleotides. The 1H 2D NMR spectra of d(CGCGAATTCGCG)2 are typical of a B DNA conformation. The 31P NMR spectrum of d(CGCGAATTCGCG)2 remains unchanged upon addition of putrescine and spermidine. However, the interaction with spermine reveals changes in the chemicals shifts of a discrete number of 31P resonances. 1H NMR titration experiments of d(CGCGAATTCGCG)2 with polyamines exhibits a similar behavior. The 15N relaxation times of 15N-labeled spermine are strongly affected by the presence of the deoxyoligonucleotide, whereas purtrescine and spermidine show similar relaxation properties in the absence and presence of d(CGCGAATTCGCG)2 . These results clearly show that spemine is the natural polyamine exhibiting binding features in the presence of the d(CGCGAATTCGCG)2 fragment. These conclusions are relevant for understanding the molecular basis of polyamine affinity and specificity and for enhanced polyamine analogs design.