title: Spectroscopic studies on interaction of BSA and Eu(III) complexes with H5ph-dtpa and H5dtpa ligands.
abstract: An novel aromatic aminopolycarboxylic acid ligand, N-(2-N,N-Dicarboxymethylaminophenyl) ethylenediamine-N,N',N'-triacetic acid (H5ph-dtpa), was synthesized by improving experimental method and its corresponding Eu(III) complex, Na2[EuIII(ph-dtpa)(H2O)]·6H2O, was successfully prepared through heat-refluxing method. As a comparison, the Eu(III) complex with diethylenetriamine-N,N,N',N',N″-pentaacetic acid (H5dtpa) ligand, Na2[Eu(III)(dtpa)(H2O)]·6H2O, was also prepared by the same method. And then, the interaction between prepared Eu(III) complexes ([EuIII(dtpa)(H2O)]2- and [EuIII(ph-dtpa)(H2O)]2-) and bovine serum albumin (BSA) in aqueous solution were studied by the combination of ultraviolet-visible (UV-vis), fluorescence and circular dichroism (CD) spectroscopies. In addition, the binding sites of Eu(III) complexes ([EuIII(dtpa)(H2O)]2- and [EuIII(ph-dtpa)(H2O)]2-) to BSA molecules were also estimated by synchronous fluorescence. Moreover, the theoretical and experimental results show that the Van der Waals, hydrogen bond and π-π stacking interactions are the mainly impulse to the reaction. The binding distances (r) between Eu(III) complexes ([EuIII(dtpa)(H2O)]2- and [EuIII(ph-dtpa)(H2O)]2-) and BSA were obtained according to Förster's non-radiative energy transfer theory. Also, the determined UV-vis absorption spectroscopy, synchronous fluorescence and circular dichroism (CD) spectra showed that the conformation of BSA could be changed in the presence of Eu(III) complexes. The obtained results can help understand the action mode between rare earth metal complexes of aminopolycarboxylic acid ligands with BSA and they are also expected to provide important information of designs of new inspired drugs.
authors.affiliation: College of Chemistry, Liaoning University, Shenyang 110036, PR China.
authors.forename: Deyong
authors.initials: D
authors.lastname: Kong
authors.affiliation: College of Chemistry, Liaoning University, Shenyang 110036, PR China.
authors.forename: Cui
authors.initials: C
authors.lastname: Qin
authors.affiliation: College of Chemistry, Liaoning University, Shenyang 110036, PR China.
authors.forename: Ping
authors.initials: P
authors.lastname: Fan
authors.affiliation: College of Chemistry, Liaoning University, Shenyang 110036, PR China.
authors.forename: Bing
authors.initials: B
authors.lastname: Li
authors.affiliation: College of Chemistry, Liaoning University, Shenyang 110036, PR China. Electronic address: wangjun888tg@126.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
mesh_terms: D000818:Animals; D002417:Cattle; D056831:Coordination Complexes / Q000737:chemistry / Q000494:pharmacology*; D015195:Drug Design; D005063:Europium / Q000737:chemistry / Q000494:pharmacology*; D008024:Ligands; D004369:Pentetic Acid / Q000737:chemistry / Q000494:pharmacology*; D011485:Protein Binding; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism*; D013050:Spectrometry, Fluorescence
chemical_list: D056831:Coordination Complexes; D008024:Ligands; D012710:Serum Albumin, Bovine; D005063:Europium; D004369:Pentetic Acid
keywords: Aminopolycarboxylic acid ligands; Bovine serum albumin (BSA); Eu(III) complexes; Fluorescence spectroscopy; Interaction