Book of Abstracts: Albany 2011
June 14-18 2011
©Adenine Press (2010)
Investigation of Interaction of Podophyllotoxins with DNA
The complex formation of podophyllotoxin and its semi synthetic derivative - etoposide with DNA has been investigated by absorption and thermal denaturation methods. The data show that these ligands have a destabilizing effect on DNA. The values of binding constant (Kb) obtained and the number of binding sites (n) of these ligands with DNA indicate that both ligands bind with DNA by two ways – specifically with limited sites of binding corresponding to intercalative (or semi-intercalative) mechanism and non specifically (external with one chains of DNA) with unlimited binding sites. For the various ways of binding to nucleic acids see references 1-5. It has been shown that the value of Kb of etoposide to DNA is higher than that of podophyllotoxin. The data obtained by these methods reveal that both ligands interact with DNA and possess a higher affinity with AT sequences.
The data obtained also show that these ligands bind with DNA immediately and the citotoxicity may be conditioned by inhibition of topoisomerses I and II of mammalian DNA, as well as a destabilization and damage to DNA itself.
Ara P. Antonyan1
1Department of Biophysics, Yerevan State University, Yerevan, 0025, Armenia