title: Interaction of prodigiosin with HSA and β-Lg: Spectroscopic and molecular docking studies.
abstract: Human serum albumin (HSA) and bovine β-lactoglobulin (β-Lg) are both introduced as blood and oral carrier scaffolds with high affinity for a wide range of pharmaceutical compounds. Prodigiosin, a natural three pyrrolic compound produced by Serratia marcescens, exhibits many pharmaceutical properties associated with health benefits. In the present study, the interaction of prodigiosin with HSA and β-Lg was investigated using fluorescence spectroscopy, circular dichroism (CD) and computational docking. Prodigiosin interacts with the Sudlow's site I of HSA and the calyx of β-Lg with association constant of 4.41 × 10(4) and 1.99 × 10(4) M(-1) to form 1:1 and 2:3 complexes at 300K, respectively. The results indicated that binding of prodigiosin to HSA and β-Lg caused strong fluorescence quenching of both proteins through static quenching mechanism. Electrostatic and hydrophobic interactions are the major forces in the stability of PG-HSA complex with enthalpy- and entropy-driving mode, although the formation of prodigiosin-β-Lg complex is entropy-driven hydrophobic associations. CD spectra showed slight conformational changes in both proteins due to the binding of prodigiosin. Moreover, the ligand displacement assay, pH-dependent interaction and protein-ligand docking study confirmed that the prodigiosin binds to residues located in the subdomain IIA and IIIA of HSA and central calyx of β-Lg.
authors.affiliation: Molecular Biotechnology Laboratory, Department of Biology, Faculty of Science, Shiraz University, PO Box: 71467-13565, Shiraz 71454, Iran.
authors.forename: Banafsheh
authors.initials: B
authors.lastname: Rastegari
authors.affiliation: Molecular Biotechnology Laboratory, Department of Biology, Faculty of Science, Shiraz University, PO Box: 71467-13565, Shiraz 71454, Iran. Electronic address: karbalaei@shirazu.ac.ir.
authors.forename: Hamid Reza
authors.initials: HR
authors.lastname: Karbalaei-Heidari
authors.affiliation: Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Yousefi
authors.affiliation: Department of Nanochemical Engineering, Faculty of Advanced Technologies, Shiraz University, Shiraz, Iran.
authors.forename: Sedigheh
authors.initials: S
authors.lastname: Zeinali
authors.affiliation: Department of Chemistry, Faculty of Science, Shiraz University, Shiraz, Iran.
authors.forename: Masoud
authors.initials: M
authors.lastname: Nabavizadeh
mesh_terms: D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D004305:Dose-Response Relationship, Drug; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007782:Lactoglobulins / Q000737:chemistry*; D062105:Molecular Docking Simulation; D011353:Prodigiosin / Q000737:chemistry* / Q000494:pharmacology; D012709:Serum Albumin / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship; D013816:Thermodynamics
chemical_list: D007782:Lactoglobulins; D012709:Serum Albumin; D011353:Prodigiosin
keywords: HSA–PG interaction; Prodigiosin; β-Lg–PG binding study