title: Analysis of binding interaction between antibacterial ciprofloxacin and human serum albumin by spectroscopic techniques.
abstract: The binding of ciprofloxacin (CFX) to human serum albumin (HSA) has been investigated by fluorescence displacement and induced circular dichroism (ICD) measurements. Displacement measurements were performed with CFX in the absence and presence of marker ligands (hemin for domain I, bilirubin for interspace of domain IA and IIA, chloroform for domain II, and diazepam for domain III) to establish CFX binding site in one of the three major domains of HSA. The primary binding site of CFX is located in site I of HSA (domain IIA) in close vicinity to the site where chloroform (CHCl3) binds. It is depicted from the decrease in quenching constant of HSA-CHCl3 system (0.02 ± 0.06) × 10(-3 )L mol(-1) compared to HSA-CFX-CHCl3 system (0.01 ± 0.06) × 10(-3 )L mol(-1) as obtained by the fluorescence displacement spectroscopy. Furthermore, far-UV CD results show that the binding of CFX leads to change in the helicity of HSA. The ICD results indicated that the CFX binds to the domain IIA of HSA which is in agreement with the fluorescence displacement results.
authors.affiliation: Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, 202002, U.P., India.
authors.forename: Ankita
authors.initials: A
authors.lastname: Varshney
authors.forename: Yunus
authors.initials: Y
authors.lastname: Ansari
authors.forename: Nida
authors.initials: N
authors.lastname: Zaidi
authors.forename: Ejaz
authors.initials: E
authors.lastname: Ahmad
authors.forename: Gamal
authors.initials: G
authors.lastname: Badr
authors.forename: Parvez
authors.initials: P
authors.lastname: Alam
authors.forename: Rizwan Hasan
authors.initials: RH
authors.lastname: Khan
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism* / Q000494:pharmacology; D001663:Bilirubin / Q000378:metabolism; D001665:Binding Sites; D002725:Chloroform / Q000378:metabolism; D002939:Ciprofloxacin / Q000378:metabolism* / Q000494:pharmacology; D003975:Diazepam / Q000378:metabolism; D006427:Hemin / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D011485:Protein Binding / Q000187:drug effects; D017433:Protein Structure, Secondary / Q000187:drug effects; D012709:Serum Albumin / Q000737:chemistry / Q000378:metabolism*; D013057:Spectrum Analysis
chemical_list: D000900:Anti-Bacterial Agents; D012709:Serum Albumin; D002939:Ciprofloxacin; D006427:Hemin; D002725:Chloroform; D003975:Diazepam; D001663:Bilirubin