Circular Dichroism and ESR Studies of Peptide Derivatives

• Main Authors: Tiffany Lin, 林筱筑
• Other Authors: L. Sheh
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/78699853495394886028

碩士 === 東海大學 === 化學系 === 96 === This thesis is divided into two major parts. The first part reports a circular dichroism (CD) study to unveil the cooperativity in 11-mer duplex DNA bearing single 5’-d(AAAA)-d(TTTT)-3’ or 5’-d(AAA)-d(TTT)-3’ binding sites. CD studies show that peptides RPyH-12 and RY-12 bind strongly to the duplex with positive cooperativity. Incubation temperature is shown to have a marked effect on observed cooperativity (Hill coefficient). The second part reports Electron Paramagnetic Resonance (EPR) studies on several new 2,6-dimethoxyhydroquinone-dipeptide conjugates that give strong EPR signals in aqueous solution containing ferrous sulfate. The facile generated semiquinone radicals are considered to be responsible for observed DNA cleavage. These new 2,6-dimethoxyhydroquinone-dipeptide conjugates should be useful in future semiquinone footprinting studies. This thesis also reports the synthesis of five new peptides bearing the XPRK motif that may be useful ligands for DNA molecular recognition studies.