[Study on the interaction of L-cysteine dipeptide with DNA].
Guang Pu Xue Yu Guang Pu Fen Xi
; 30(1): 146-9, 2010 Jan.
Article
em Zh
| MEDLINE
| ID: mdl-20302102
ABSTRACT
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 x 10(4) L x 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.
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Base de dados:
MEDLINE
Assunto principal:
Espectrometria de Fluorescência
/
DNA
/
Cisteína
Idioma:
Zh
Ano de publicação:
2010
Tipo de documento:
Article