Porphyrins as spectroscopic sensors for conformational studies of DNA*
Milan Balaz, Klaus Bitsch-Jensen, Angela Mammana, George A. Ellestad, Koji Nakanishi, and Nina Berova
Department of Chemistry, Columbia University, 3000 Broadway, New York, NY 10027, USA
Abstract: Molecular systems containing two or more interacting porphyrins show remarkable spectroscopic features that allow for a very sensitive detection of conformational changes on the microscale level by different methods, such as fluorescence and electronic circular dichroism (ECD). Covalent porphyrin-DNA assemblies can provide a CD profile (exciton couplet) within the porphyrin Soret band region which is very diagnostic for DNA conformational changes. Additionally, covalently linked porphyrins have been shown to function as DNA molecular caps and to stabilize the non-self-complementary non-Watson-Crick guanine-adenine DNA sequence via their strong π-π stacking.
Keywords: porphyrins; circular dichroism; DNA conformation; DNA probe; B- to Z-DNA transition; oligonucleotides; DNA conjugates.
*Pure Appl. Chem. 79, 467-823 (2007) pp. 467-823. An issue of reviews and research papers based on lectures presented at the 25th International Symposium on Chemistry of Natural Products (ISCNP-25) and 5th International Conference on Biodiversity (ICOB-5), held jointly in Kyoto, Japan, 23-28 July 2006, on the theme of natural products.