Interaction of proteins with ionic liquid, alcohol and DMSO and in situ generation of gold nano-clusters in a cell

Abstract

In this review, we give a brief overview on how the interaction of proteins with ionic liquids, alcohols and dimethyl sulfoxide (DMSO) influences the stability, conformational dynamics and function of proteins/enzymes. We present experimental results obtained from fluorescence correlation spectroscopy on the effect of ionic liquid or alcohol or DMSO on the size (more precisely, the diffusion constant) and conformational dynamics of lysozyme, cytochrome c and human serum albumin in aqueous solution. The interaction of ionic liquid with biomolecules (e.g. protein, DNA etc.) has emerged as a current frontier. We demonstrate that ionic liquids are excellent stabilizers of protein and DNA and, in some cases, cause refolding of a protein already denatured by chemical denaturing agents. We show that in ethanol-water binary mixture, proteins undergo non-monotonic changes in size and dynamics with increasing ethanol content. We also discuss the effect of water-DMSO mixture on the stability of proteins. We demonstrate how large-scale molecular dynamics simulations have revealed the molecular origin of this observed phenomenon and provide a microscopic picture of the immediate environment of the biomolecules. Finally, we describe how favorable interactions of ionic liquids may be utilized for in situ generation of fluorescent gold nano-clusters for imaging a live cell.

Changes in Cryopreserved Cell Nuclei Serve as Indicators of Processes during Freezing and Thawing

“…The second major damaging event recognized during cell freezing was the propagation of intracellular and extracellular ice crystals. 15 The mechanisms of cell damage from intracellular and extracellular ice include physical destruction of membranes and organelle disruption. 15 Fortunately, the freezing process in cells is strongly affected by velocity of the freezing/cooling and the cryoprotective additives, due to which a multitude of cells from prokaryotic and eukaryotic organisms can be recovered from temperatures as low as almost 200 °C below freezing point when the cryoprotectants are present.…”

“…15 The mechanisms of cell damage from intracellular and extracellular ice include physical destruction of membranes and organelle disruption. 15 Fortunately, the freezing process in cells is strongly affected by velocity of the freezing/cooling and the cryoprotective additives, due to which a multitude of cells from prokaryotic and eukaryotic organisms can be recovered from temperatures as low as almost 200 °C below freezing point when the cryoprotectants are present. 10,16 The mechanism of action of the cryoprotectants is complex; however, they appear to act primarily within the cells or in their immediate surroundings.…”

“…Moreover, when the concentration of ions and other solvents increases beyond physiological concentrations, the following stress may be toxic for cells. The second major damaging event recognized during cell freezing was the propagation of intracellular and extracellular ice crystals . The mechanisms of cell damage from intracellular and extracellular ice include physical destruction of membranes and organelle disruption …”

Applicability of Ionic Liquids in Topical Drug Delivery Systems: A Mini Review

“…Furthermore, the in vivo pharmacodynamic analysis demonstrated an important haemostatic activity of Dencichine by topical application, as well as, a reduced cell toxicity and skin irritation. These results show once again, that ILs may have multiple utilities when incorporated in topical Delivery systems [44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63].…”

A Fast and Easy-To-Go Method for the Preparation of Au Nanocluster and Its Application for Fe(III) Cation Sensing

“…As a class of novel nanomaterials, luminescent metal nanoclusters have drawn much research attention in fields of optical sensing, imaging, biolabeling, and therapy ( Nandi et al, 2018 ; Zhang et al, 2018 ). Since the size of these nanoclusters is comparable to the Fermi wavelength of electrons, molecular-like behavior is usually observed from these nanoclusters such as separated electronic states and size-dependent electronic transitions, which endows them with different optical features from those of nanoparticles.…”