Nucleic Acids Research, 2003, Vol. 31, No. 11 2725-2734
© 2003 Oxford University Press
Syntheses and structural studies of calix[4]arene–nucleoside and calix[4]arene–oligonucleotide hybrids
National Research Laboratory, Department of Chemistry, Division of Molecular and Life Sciences, Pohang University of Science and Technology, San 31 Hyoja Dong, Pohang 790-784, Korea
*To whom correspondence should be addressed. Tel: +82 54 279 2115; Fax: +82 54 279 3399; Email: bhkim{at}postech.ac.kr
We have synthesized three types of calix[4]arene– nucleoside hybrid efficiently by amide bond formation between the amine functional groups of 1,3-diaminocalix[4]arene and the carboxyl groups of thymidine nucleoside derivatives. X-ray crystallography of a homocoupled calix[4]arene–nucleoside hybrid revealed an interesting hydrogen bonding pattern between thymine bases and the amide linkages. We designed the calix[4]arene–oligonucleotide hybrids (5'-AAAAGATATCAAXTTGATATCTTTT-3', 5'-T12-X-T12-3', and 5'-A12-X-T12-3') to be V-shaped oligodeoxyribonucleotides and synthesized them by using a calix[4]arene–nucleoside hybrid (X) as a key building block. Thermal denaturation experiments, monitored by UV spectroscopy at 260 and 284 nm, and circular dichroism spectra of the calix[4]arene–oligonucleotide hybrids suggest that the modified oligonucleotides indeed adopt V-shaped conformations, making them suitable for use as building blocks in the construction of programmed oligonucleotide nanostructures.