Yingying Chai1,2, Dasharath Kondhare1, Aigui Zhang1, Peter Leonard1, Frank Seela1,3. 1. Laboratory of Bioorganic Chemistry and Chemical Biology, Center for Nanotechnology, Heisenbergstrasse 11, 48149, Münster, Germany. 2. Department of Respiratory, Critical Care Medicine Targeted Tracer, Research and Development Laboratory, West China Hospital, Sichuan, 610041, P. R. China. 3. Laboratorium für Organische und Bioorganische Chemie, Institut für Chemie neuer Materialien, Universität Osnabrück, Barbarastrasse 7, 49069, Osnabrück, Germany.
Abstract
Stabilization of DNA is beneficial for many applications in the fields of DNA therapeutics, diagnostics, and materials science. Now, this phenomenon is studied on heterochiral DNA, an autonomous DNA recognition system with complementary strands in α-D and β-D configuration showing parallel strand orientation. The 12-mer heterochiral duplexes were constructed from anomeric (α/β-D) oligonucleotide single-strands. Purine-2,6-diamine and 8-aza-7-deaza-7-bromopurine-2,6-diamine 2'-deoxyribonucleosides having the capability to form tridentate base pairs with dT were used to strengthen the stability of the dA-dT base pair. Tm data and thermodynamic values obtained from UV melting profiles indicated that the 8-aza-7-deaza 2'-deoxyribonucleoside decorated with a bromo substituent is so far the most efficient stabilizer for heterochiral DNA. Compared with that, the stabilizing effect of the purine-2,6-diamine 2'-deoxyribonucleoside is low. Global changes of helix structures were identified by circular dichroism (CD) spectra during melting.
Stabilization of DNA is beneficial for many applications in the fields of DNA therapeutics, diagnostics, and materials science. Now, this phenomenon is studied on heterochiral DNA, an autonomous DNA recognition system with complementary strn class="Chemical">ands in α-D and β-D configuration showing parallel strand orientation. The 12-mer heterochiral duplexes were constructed from anomeric (α/β-D) oligonucleotide single-strands. Purine-2,6-diamineand8-aza-7-deaza-7-bromopurine-2,6-diamine 2'-deoxyribonucleosides having the capability to form tridentate base pairs with dT were used to strengthen the stability of the dA-dT base pair. Tm data and thermodynamic values obtained from UV melting profiles indicated that the 8-aza-7-deaza 2'-deoxyribonucleoside decorated with a bromo substituent is so far the most efficient stabilizer for heterochiral DNA. Compared with that, the stabilizing effect of the purine-2,6-diamine 2'-deoxyribonucleoside is low. Global changes of helix structures were identified by circular dichroism (CD) spectra during melting.