Interaction of cromolyn sodium with human serum albumin: A fluorescence quenching study

• Published in: Bioorganic & medicinal chemistry 2005-12, Vol.13 (24), p.6609-6614
• Main Authors: Hu, Yan-Jun, Liu, Yi, Pi, Zhen-Bang, Qu, Song-Sheng
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Cromolyn sodium; Cromolyn Sodium - chemistry; Energy Transfer; Fluorescence quenching; Fluorescence resonance energy transfer; Fundamental and applied biological sciences. Psychology; Histamine and antagonists. Allergy; Human serum albumin; Humans; Interactions. Associations; Intermolecular phenomena; Medical sciences; Molecular biophysics; Molecular Structure; Pharmacology. Drug treatments; Protein Binding; Serum Albumin - chemistry; Spectrometry, Fluorescence; Static Electricity; Thermodynamic parameters
• ISSN: 0968-0896; 1464-3391
• DOI: 10.1016/j.bmc.2005.07.039

An interaction between cromolyn sodium with human serum albumin was investigated by spectroscopic methods. The thermodynamic parameters at different temperatures and energy transfer parameters are provided. The interaction between cromolyn sodium (CS) and human serum albumin (HSA) was investigated using tryptophan fluorescence quenching. In the discussion of the mechanism, it was proved that the fluorescence quenching of HSA by CS is a result of the formation of a CS–HSA complex. Quenching constants were determined using the Sterns–Volmer equation to provide a measure of the binding affinity between CS and HSA. The thermodynamic parameters Δ G, Δ H, and Δ S at different temperatures were calculated. The distance r between donor (Trp 214) and acceptor (CS) was obtained according to fluorescence resonance energy transfer (FRET). Furthermore, synchronous fluorescence spectroscopy data and UV–vis absorbance spectra have suggested that the association between CS and HSA changed the molecular conformation of HSA and the electrostatic interactions play a major role in CS–HSA association.