Binding of 8-methoxypsoralen to DNA in vitro: Monitoring by spectroscopic and chemometrics approaches

• Published in: Journal of luminescence Vol. 154; pp. 116 - 123
• Main Authors: Zhou, Xiaoyue, Zhang, Guowen, Wang, Langhong
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.2014; Elsevier
• Subjects: 8-Methoxypsoralen; Analytical, structural and metabolic biochemistry; Binding mode; Biological and medical sciences; Calf thymus DNA; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Dna, deoxyribonucleoproteins; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Multi-spectroscopic technique; Multivariate curve resolution-alternating least-squares; Nucleic acids; Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Photoluminescence; Physics; Solid-liquid transitions; Specific phase transitions; Binding mode; 8-Methoxypsoralen; Multivariate curve resolution-alternating least-squares; Calf thymus DNA; Multi-spectroscopic technique; Viscosity; Fourier transform spectroscopy; Fourier transformation; Enthalpy; Fluorescence; Entropy; Acridine dye; Hydrogen bonds; Molybdenum phosphide; Absorption spectra; Least square fit; Depth profiles; Monitoring; Cadmium; Melting; Van der Waals forces; Ultraviolet spectra; Theoretical study; Infrared spectra; Biological activity; Circular dichroism; Acridine orange; Ultraviolet radiation; DNA; Aluminium sulfide; Conformation; Concentration distribution
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2014.04.017

8-Methoxypsoralen (8-MOP) is a naturally occurring furanocoumarin with a variety of biological and pharmacological activities. The binding mechanism of 8-MOP to calf thymus DNA (ctDNA) at physiological pH was investigated by multi-spectroscopic techniques including UV–vis absorption, fluorescence, circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy along with DNA melting studies and viscosity measurements. The multivariate curve resolution-alternating least squares (MCR-ALS) chemometrics approach was introduced to resolve the expanded UV–vis spectral data matrix, and both the pure spectra and the equilibrium concentration profiles for the components (8-MOP, ctDNA and 8-MOP-ctDNA complex) in the system were successfully obtained to monitor the 8-MOP-ctDNA interaction. The results suggested that 8-MOP could bind to ctDNA via intercalation binding as evidenced by significant increases in melting and relative viscosity of ctDNA and competitive study using acridine orange (AO) as a fluorescence probe. The positive values of enthalpy and entropy change suggested that hydrogen bonds and van der Waals forces played a predominant role in the binding process. Further, FT-IR and CD spectra analysis indicated that 8-MOP preferentially bound to A–T base pairs with no major perturbation in ctDNA double helix conformation. Moreover, molecular docking was employed to exhibit the specific binding mode of 8-MOP to ctDNA intuitively. •The interaction processes of 8-MOP with ctDNA was monitored by MCR-ALS approach.•The binding mode of 8-MOP to ctDNA was an intercalation.•8-MOP most likely bound to adenine and thymine base pairs of ctDNA.•Molecular docking illustrated the specific binding.