Transition of a compact intermediate state of pea lectin under the influence of different molecular weight polyethylene glycols

Solvent Perturbation of Protein Structures - A Review Study with Lectins

Use of organic molecules as co-solvent with water, the ubiquitous biological solvent, to perturb the structure of proteins is popular in the research area of protein structure and folding. These organic co-solvents are believed to somehow mimic the environment near the cell membrane. Apart from that they induce non-native states which can be present in the protein folding pathway or those states also may be representative of the off pathway structures leading to amyloid formation, responsible for various fatal diseases. In this review, we shall focus on organic co-solvent induced structure perturbation of various members of lectin family. Lectins are excellent model systems for protein folding study because of its wide occurrence, diverse structure and versatile biological functions. Lectins were mainly perturbed by two fluoroalcohols - 2,2,2- trifluoroethanol and 1,1,1,3,3,3-hexafluoroisopropanol whereas glycerol, ethylene glycol and polyethylene glycols were used in some cases. Overall, all native lectins were denatured by alcohols and most of the denatured lectins have predominant helical secondary structure. But characterization of the helical states and the transition pathway for various lectins revealed diverse result.

A novel amalgamation of deep eutectic solvents and crowders as biocompatible solvent media for enhanced structural and thermal stability of bovine serum albumin

This study unravels the effect of a novel solvent medium designed by amalgamation of macromolecular crowders and deep eutectic solvents (DESs) on bovine serum albumin (BSA).

Characterization of intermediate state of myoglobin in the presence of PEG 10 under physiological conditions

The macromolecular crowding progressively has been gaining prominence in recent years as it acts as a sword with double-edge on protein stability and folding, i.e., showing assorted results of having both stabilizing and destabilizing effects. We studied the effects of different concentrations of polyethylene glycol (PEG-10) on structure and stability of myoglobin. The tertiary structure of myoglobin was found to be perturbed in the presence of polyethylene glycol, however there was insignificant change in the secondary structure. It was observed that polyethylene glycol induces molten globule state in myoglobin, where the intermediate state holds hydrophobic patches and larger hydrodynamic volume as compared to the native protein. In addition, isothermal titration calorimetry (ITC) showed strong binding between myoglobin and polyethylene glycol, at the physiological pH. We hypothesize that polyethylene glycol induces molten globule conformation in myoglobin by interacting with heme group of myoglobin. We caution that the binding of protein with crowder and other soft interactions need to be gravely well thought-out when studying macromolecular crowding. In our case, destabilizing protein-crowder interactions could compete and overcome the stabilizing exclusion volume effect.