@article{178, keywords = {Binding Sites, Circular Dichroism, Humans, Indole Alkaloids, Models, Molecular, Molecular Docking Simulation, Protein Binding, Protein structure, Tertiary, Quinazolines, Serum Albumin, Spectrophotometry, Ultraviolet, Stereoisomerism}, author = {Celesztina Domonkos and Ilona Fitos and Júlia Visy and Ferenc Zsila}, title = {Role of the conformational flexibility of evodiamine in its binding to protein hosts: a comparative spectroscopic and molecular modeling evaluation with rutaecarpine.}, abstract = {
Spectroscopic studies combined with computational analysis indicate the inherent conformational flexibility of the β-carbolin derivative evodiamine (EVD) featured with diverse pharmacological activities. Qualitative evaluation of the circular dichroism (CD) spectra of EVD enantiomers complemented with quantum chemical calculations reveals a chiral exciton signature that can be assigned to the folded, L-shaped conformation of the molecule. Changes of the exciton couplet measured in different solvents and the near-UV CD profile upon binding to human serum albumin (HSA) refer to the structural adaptability of EVD. The enantioselectivity of EVD-HSA interaction is demonstrated showing the binding preference of the (R)-enantiomer. Comparison of experimental and calculated CD spectra of various conformers of EVD as well as the results of molecular docking data suggest that the (R)-antipode is accomodated within the IIA subdomain of HSA in ridge-tile conformation. Rutaecarpine (RTC), the close congener of EVD, forms much tighter association complexes both with HSA and α1-acid glycoprotein. In contrast to EVD, the nearly planar geometry of the indoloquinazoline ring system of RTC allows its stacked dimeric binding to the HSA.
}, year = {2014}, journal = {Phys Chem Chem Phys}, volume = {16}, pages = {22632-42}, month = {2014 Nov 7}, issn = {1463-9084}, doi = {10.1039/c4cp02483d}, }