Spectroscopy and Spectral Analysis, Volume. 30, Issue 1, 146(2010)
Study on the Interaction of L-Cysteine Dipeptide with DNA
In the present paper the interaction mechanism and mode of biologically active cysteine dipeptide (Cys-Cys) with DNA was studied by UV-Vis spectrophotometry and fluorescence spectroscopy using ethidium bromide as a fluorescence probe. The results showed that in the buffer solution of Tris-HCl (pH 7.20),at low concentration of Cys-Cys,the ultraviolet spectrum of DNA-Cys-Cys system produced hypochromic effect with increasing the concentration of Cys-Cys. When the concentration of Cys-Cys increased to some high extent,the ultraviolet spectrum of DNA-Cys-Cys system produced hyperchromic effect. Salt-effect experiment showed that the interaction is liable to be affected by the ionic strengths,suggesting the existence of electrostatic binding between Cys-Cys and DNA. The fluorescence of EB-DNA had quenching effect with increasing the concentration of Cys-Cys,and the Stern-Volmer equation indicated that the quenching process was a static one. According to the Lineweaver-Burk equation the binding constant was determined to be 1.640×104 L·mol-1. From the above results it can be concluded that the interaction mode of Cys-Cys with DNA was mainly electrostatic binding. These findings could contribute to further investigation on the mechanism of oligopeptides interaction with DNA.
Get Citation
Copy Citation Text
LU Kui, CHENG Hong-li, MA Li, ZHAO Dong-xin, YANG Liang-ru, ZHAO Yu-fen. Study on the Interaction of L-Cysteine Dipeptide with DNA[J]. Spectroscopy and Spectral Analysis, 2010, 30(1): 146
Received: Jan. 29, 2009
Accepted: --
Published Online: Jul. 13, 2010
The Author Email: Kui LU (luckyluke@haut.edu.cn)