Study on the Interaction of Vitamin B12 with DNA by Spectroscopy and Electrochemical Methods

✍ Scribed by Reza Hajian; Mitra Zafari

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 226 KB
• Volume: 29
• Category: Article
• ISSN: 0256-7660
• DOI: 10.1002/cjoc.201180254

✦ Synopsis

The Interaction between vitamin B 12 (VB 12 ) and fish sperm DNA was investigated in physiological buffer (pH 7.4) using the methylene blue (MB) dye as a spectral probe by spetcrophotometery, viscosity measurements and cyclic voltammetry. The apparent binding constant of vitamin B 12 with DNA was found to be 3.2×10 5 mol -1 •L. The voltammetric behavior of vitamin B 12 has been investigated at glassy carbon electrode using cyclic voltammetry. Thermodynamic parameters including ∆H 0 , ∆S 0 and ∆G 0 for the interaction between VB 12 and DNA have determined as -2.3×10 4 , 27.54 and -3.1×10 4 J•mol -1 •K -1 respectively. One indication of DNA binding mode with VB 12 was the change in viscosity when a small molecule associates with DNA. The diffusion coefficients of VB 12 in the absence (D 0 ) f and presence of DNA (D 0 ) b was calculated as 5.04×10 -6 and 1.13×10 -6 cm 2 •s -1 respectively.

The results indicated that vitamin B 12 can bind to DNA and the major binding mode was intercalative binding.