Spectroscopic insight into the interaction of bovine serum albumin with imidazolium‐based ionic liquids in aqueous solution

Abstract

The study of protein–ionic liquid interactions is very important because of the widespread use of ionic liquids as protein stabilizer in the recent years. In this work, the interaction of bovine serum albumin (BSA) with different imidazolium‐based ionic liquids (ILs) such as [1‐ethyl‐3‐methyl‐imidazolium ethyl sulfate (EmimESO4), 1‐ethyl‐3‐methyl‐imidazolium chloride (EmimCl) and 1‐butyl‐3‐methyl‐imidazolium chloride (BmimCl)] has been investigated using different spectroscopic techniques. The intrinsic fluorescence of BSA is quenched by ILs by the dynamic mechanism. The thermodynamic analysis demonstrates that very weak interactions exist between BSA and ILs. 8‐Anilino‐1‐naphthalenesulfonic acid (ANS) fluorescence and lifetime measurements reveal the formation of the compact structure of BSA in IL medium. The conformational changes of BSA were monitored by CD analysis. Temperature‐dependent ultraviolet (UV) measurements were done to study the thermal stability of BSA. The thermal stability of BSA in the presence of ILs follows the trend EmimESO4 > EmimCl > BmimCl and in the presence of more hydrophobic IL, destabilization increases rapidly as a function of concentration.

Heme Dissociation from Myoglobin in the Presence of the Zwitterionic Detergent N,N-Dimethyl-N-Dodecylglycine Betaine: Effects of Ionic Liquids

“…Ionic liquids have been demonstrated to exhibit properties similar to typical electrolytic salts following the Hofmeister series when combined in aqueous solution with proteins [24,25,26,27,28]. Depending on the structure of the cation-anion molecules, ILs have also exhibited the ability to phase-partition between organic and aqueous phases, or to aggregate and micellize in a manner similar to detergents [19,21,29,30,31,32,33,34,35,36]. The micellization activity is primarily driven through the alkyl chains attached to the cation component of the IL [35].…”

“…Numerous recent studies, both experimental and computational, have focused on the interactions of ILs with proteins [11,26,30,33]. Many groups have investigated the interactions of different ILs with industrially relevant proteins and enzymes such as laccase [34], thermolysin [29], lipase [37], and as additives to promote protein crystallization [38,39].…”

Luminescent Palladacycles Containing a Pyrene Chromophor; Synthesis, Biological and Computational Studies of the Interaction with DNA and BSA

“…The first peak at 200–240 nm region is characteristic of the polypeptide backbone of the protein and is associated with the π–π* transition. The second peak at 260–300 nm region, which is related to the aromatic amino acids such as tryptophan (Trp), tyrosine (Tyr), and phenylalanine (Phe), is due to the n–π* transition . The absorption maximum of BSA at about 280 nm is extremely sensitive to the surrounding microenvironment and any fine variation in this absorption band indicates a perturbation in the aromatic amino acid residues.…”

Insights into the binding interaction between copper ferrite nanoparticles and bovine serum albumin: An effect on protein conformation and activity

“…CuFe 2 O 4 NP), K SV denotes the Stern–Volmer quenching constant. [Q] is the concentration of CuFe 2 O 4 , τ 0 is the average lifetime of BSA without CuFe 2 O 4 NP (which is equal to 5.98 nsec for BSA as per results obtained from lifetime measurements) and k q refers to the bimolecular quenching rate constant …”

“…Trp‐134 and 213 are located in the BSA amino acid sequence. Due to its low cost, high stability, availability, water solubility, exceptional ligand binding capability and 80% sequence similarity with human serum albumin (HSA), BSA has been extensively investigated as a model protein in various interaction studies …”