Related Experiment Video
Updated: Jan 31, 2026
Synthesis of Bimetallic Pt/Sn-based Nanoparticles in Ionic Liquids
Published on: August 23, 2018
Insight into impact of choline-based ionic liquids on bovine β-lactoglobulin structural analysis: Unexpected high
Anamika Sindhu1, Navin Kumar Mogha1, Pannuru Venkatesu1
1Department of Chemistry, University of Delhi, Delhi 110007, India.
Insights
Cholinium-based ionic liquids (ILs) significantly impact beta-lactoglobulin (β-LG) stability. Certain ILs enhance thermal stability, while others can destabilize the protein structure, offering insights for biocatalysis.
Area of Science:
- Biochemistry
- Materials Science
Background:
- Beta-lactoglobulin (β-LG) is a key protein model for studying protein stability.
- Ionic liquids (ILs) are tunable solvents with potential applications in biomaterials and biocatalysis.
- Understanding the interaction between ILs and proteins is crucial for protein engineering and industrial applications.
Purpose of the Study:
- To investigate the effects of various cholinium-based ionic liquids (ILs) on the structural and thermal stability of β-lactoglobulin (β-LG).
- To elucidate the role of IL anions in modulating protein stability.
- To explore the potential of ILs as green solvents in biocatalytic processes.
Main Methods:
- Differential scanning calorimetry (DSC) to assess thermal stability (Tm).
- Spectroscopic techniques and dynamic light scattering (DLS) to analyze structural changes and biomolecular interactions.
- Estimation of thermodynamic parameters (ΔuG, ΔuH, ΔCp, ΔuS) for protein unfolding.
- Molecular docking studies using AutoDock Vina to predict binding conformations.
Main Results:
- Choline dihydrogen phosphate [Chn][Dhp] and choline bitartrate [Chn][Bit] significantly enhanced β-LG thermal stability, increasing Tm to ~93°C from 72.48°C.
- Choline acetate [Chn][Ac] and choline chloride [Chn][Cl] also increased thermal stability.
- Choline iodide [Chn][I] showed complex behavior with two endothermic peaks, preventing Tm calculation.
- Choline hydroxide [Chn][OH] acted as a complete destabilizer for β-LG.
Conclusions:
- The anion of the cholinium-based IL plays a critical role in determining the effect on β-LG structural and thermal stability.
- Specific ILs, such as [Chn][Dhp] and [Chn][Bit], can effectively stabilize β-LG, suggesting their potential use in industrial biocatalysis.
- The findings provide valuable insights into protein-IL interactions, aiding in the design of green solvents for protein stabilization and biocatalytic applications.
Abstract:
In this present work, we report the effects of different concentrations of various cholinium-based ionic liquids (ILs) on the structural and thermal stability of β-lactoglobulin (β-LG). Results indicated that anions in ILs have played an important role in affecting the thermal and structural stability of β-LG. Biomolecular interactions between β-LG and ILs are carried out by differential scanning calorimetry (DSC), different spectroscopic and dynamic light scattering (DLS). Analysis of experimental data revealed that an excellent thermal stability of β-LG is obtained in presence of choline dihydrogen phosphate [Chn][Dhp] and choline bitartrate [Chn][Bit] where Tm value of β-LG increased to 93.58 and 93.22 °C, respectively, as compared to Tm of β-LG in buffer at 72.48 °C. Similarly, in presence of choline acetate [Chn][Ac] and choline chloride [Chn][Cl] thermal stability of β-LG also increased, however, it was not possible to calculate Tm values in case of choline iodide [Chn][I], because of obtaining two endothermic peaks in DSC curves. On the other hand, choline hydroxide [Chn][OH] acts as complete destabilizer for β-LG native structure as no Tm is obtained in its presence. The obtained results are further confirmed by estimating the thermodynamic parameters such as Gibbs free energy of unfolding (ΔuG), enthalpy of unfolding (ΔuH), heat capacity change (ΔCp) and total entropy change during protein unfolding (ΔuS). Molecular docking studies of β-LG and various choline-based ILs are also performed to know the probable binding conformations using AutoDock Vina and AutoDock tools 1.5.6, results obtained are in correlation with spectroscopic and biothermodynamic data. The combined study by DSC, spectroscopy techniques and molecular docking studies suggest that some of these ILs can be used as industrial green solvents for different biocatalytic processes and also can help in resolving the problems involving protein unfolding and thermal stability studies.
Related Concept Videos
02:15Protein and Protein Structure
A protein's shape is critical to its function. For example, an enzyme...
02:42Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
01:14Stability of structures
02:54Molecular and Ionic Solids
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
03:10Ionic Radii
00:42Ionic Bonds
When atoms gain or lose electrons to achieve a more stable electron configuration they form ions. Ionic bonds are electrostatic attractions between ions with opposite charges. Ionic compounds are rigid and brittle when solid and may dissociate into their constituent ions in water. Covalent compounds, by contrast, remain intact unless a chemical reaction breaks them.
Opposing Charges Hold Ions Together in Ionic Compounds
Ionic bonds are reversible electrostatic interactions between ions...