title: Studying the interaction between three synthesized heterocyclic sulfonamide compounds with hemoglobin by spectroscopy and molecular modeling techniques.
abstract: The interaction between synthesized heterocyclic benzene sulfonamide compounds, N-(7-benzyl-56-biphenyl-2m-tolyl-7H-pyrrolo[23-d]pyrimidine-4-yl)-benzene sulfonamide (HBS1), N-(7-benzyl-56-biphenyl-2-m-tolyl-7H-pyrrolo[23-d] pyrimidine-4-yl)-4-methyl- benzene sulfonamide (HBS2), and N-(7-benzyl-56-biphenyl-2-m-tolyl-7H-pyrrolo[23-d]pyrimidine-4-yl)-4-chloro-benzene sulfonamide (HBS3) with Hb was studied by fluorescence quenching, zeta potentional, circular dichroism, and molecular modeling techniques. The fluorescence spectroscopy experiments were performed in order to study the conformational changes, possibly due to a discrete reorganization of Trp residues during binding between HBS derivatives and Hb. The variation of the KSVvalue suggested that hydrophobic and electrostatic interactions were the predominant intermolecular forces stabilizing the complex. The KSV1ans KSV2values of HBS derivatives with Hb are .6 × 1013and 3 × 1013M-1for Hb-HBS1, 1 × 1013and 4 × 1013M-1for Hb-HBS2, .9 × 1013, and 6 × 1013M-1for Hb-HBS3, respectively. The molecular distances between Hb and HBS derivatives in binary and ternary systems were estimated according to Förster's theory of dipole-dipole non-radiation energy transfer. The quantitative analysis data of circular dichroism spectra demonstrated that the binding of the three HBS derivatives to Hb induced conformational changes in Hb. Changes in the zeta potential of the Hb-HBS derivatives complexes demonstrated a hydrophobic adsorption of the anionic ligand onto the surface of Hb as well as both electrostatic and hydrophobic adsorption in the case of the complex. The modeling data thus confirmed the experimental results. This study is expected to provide important insight into the interaction of Hb with three HBS derivatives to use in various toxicological and therapeutic processes.
authors: a Faculty of Sciences, Department of Biochemistry and Biophysics, Mashhad Branch , Islamic Azad University , Mashhad , Iran.
authors: Samane
authors: S
authors: Naeeminejad
authors: a Faculty of Sciences, Department of Biochemistry and Biophysics, Mashhad Branch , Islamic Azad University , Mashhad , Iran.
authors: Reza
authors: R
authors: Assaran Darban
authors: a Faculty of Sciences, Department of Biochemistry and Biophysics, Mashhad Branch , Islamic Azad University , Mashhad , Iran.
authors: Sima
authors: S
authors: Beigoli
authors: b Medical Chemistry Department , School of Pharmacy, Mashhad University of Medical Sciences , Mashhad , Iran.
authors: Mohammad Reza
authors: MR
authors: Saberi
authors: a Faculty of Sciences, Department of Biochemistry and Biophysics, Mashhad Branch , Islamic Azad University , Mashhad , Iran.
authors: Jamshidkhan
authors: J
authors: Chamani
mesh_terms: D001665:Binding Sites; D002942:Circular Dichroism; D006454:Hemoglobins / Q000737:chemistry*; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D062105:Molecular Docking Simulation; D011485:Protein Binding; D000072417:Protein Domains; D017433:Protein Structure, Secondary; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence; D013449:Sulfonamides / Q000737:chemistry*
chemical_list: D006454:Hemoglobins; D013449:Sulfonamides
keywords: HBS derivatives; hemoglobin; molecular modeling; spectroscopic methods