By means of ultraviolet–visible (UV-Vis) and fluorescence spectra, the binding ratio between vitamin K3 and herring-sperm DNA in a physiological pH environment (pH = 7.40) was determined as nK3:nDNA = 2:1, and the binding constants of vitamin K3 binding to DNA at different temperatures were determined as Kθ298K = 1.28 × 105 L·mol−1 and Kθ310K = 7.19 × 104 L·mol−1, which were confirmed using the double reciprocal method are ΔrHmθ = −3.57 × 104 J·mol−1, ΔrGmθ = −2.92 × 104 J·mol−1, and ΔrSmθ = 217.67 J·mol−1K−1. The driving power of this process was enthalpy. An intercalation binding of the vitamin K3 with DNA was supported by a competitive experiment using acridine orange (AO) as a spectral probe. By combination analysis of the Scatchard method and cyclic voltammetry, we suggested that the interaction mode between vitamin K3 and herring-sperm DNA would be a mixed mode. The quinonoid, duality fused-ring of vitamin K3 can intercalate into the base pairs of DNA, and there is an electrostatic binding along with intercalation binding.
Vol. 5, Iss. 14 Virtual Journal for Biomedical Optics
Jianhang Huang, Xingming Wang, Dan Fei, and Lisheng Ding, "Interactions of Vitamin K3 with Herring-Sperm DNA Using Spectroscopy and Electrochemistry," Appl. Spectrosc. 64, 1126-1130 (2010)