Protein-nanoparticle interactions and a new insight.

The study of protein-nanoparticle interactions provides knowledge about the bio-reactivity of nanoparticles, and creates a database of nanoparticles for applications in nanomedicine, nanodiagnosis, and nanotherapy. The problem arises when nanoparticles come in contact with physiological fluids such as plasma or serum, wherein they interact with the proteins (or other biomolecules). This interaction leads to the coating of proteins on the nanoparticle surface, mostly due to the electrostatic interaction, called 'corona'.

Structural insights into SARS-CoV-2 proteins.

The unprecedented scale of the ongoing COVID-19 pandemic has catalyzed an intense effort of the global scientific community to unravel different aspects of the disease in a short time. One of the crucial aspects of these developments is the determination of more than three hundred experimental structures of SARS-CoV-2 proteins in the last few months. These include structures of viral non-structural, structural, and accessory proteins and their complexes determined by either X-ray diffraction or cryo-electron microscopy.

Role of surface charges on interaction of rod-shaped magnetic hydroxyapatite nanoparticles with protein.

Magnetic hydroxyapatite (MHAp) exhibits excellent biocompatibility, making it an ideal candidate as a biomaterial. Recent investigations have shown that the combined effect of magnetite and hydroxyapatite nanostructures provide efficient means for diagnostic and therapeutic applications which can be controlled with an external magnetic field. For these applications an important aspect to be considered is the interaction of the MHAp nanoparticles (NPs) with biomolecules such as protein (P) and the subsequent biological response.

drFrnE Represents a Hitherto Unknown Class of Eubacterial Cytoplasmic Disulfide Oxido-Reductases.

Aims: Living cells employ thioredoxin and glutaredoxin disulfide oxido-reductases to protect thiol groups in intracellular proteins. FrnE protein of Deinococcus radiodurans (drFrnE) is a disulfide oxido-reductase that is induced in response to Cd exposure and is involved in cadmium and radiation tolerance. The aim of this study is to probe structure, function, and cellular localization of FrnE class of proteins.

Differential sensitivity of Chironomus and human hemoglobin to gamma radiation.

Chironomus ramosus is known to tolerate high doses of gamma radiation exposure. Larvae of this insect possess more than 95% of hemoglobin (Hb) in its circulatory hemolymph. This is a comparative study to see effect of gamma radiation on Hb of Chironomus and humans, two evolutionarily diverse organisms one having extracellular and the other intracellular Hb respectively.

Unfolding and inactivation of proteins by counterions in protein-nanoparticles interaction.

In this work, the structure and activity of proteins; such as, hen egg lysozyme (HEWL) and calf intestine alkaline phosphatase (CIAP); have been investigated after incubation with surface coated iron oxide nanoparticles (IONPs) in water. IONPs were coated with counterions bound charge-ligands and were named as the charge-ligand counterions iron oxide nanoparticles (CLC-IONPs). The coating was done with tri-lithium citrate (TLC) and tri-potassium citrate (TKC) to have negative surface charge of CLC-IONPs and Li(+) and K(+), respectively, as counterions.

Purification, crystallization and preliminary crystallographic investigation of FrnE, a disulfide oxidoreductase from Deinococcus radiodurans.

In prokaryotes, Dsb proteins catalyze the formation of native disulfide bonds through an oxidative folding pathway and are part of the cell machinery that protects proteins from oxidative stress. Deinococcus radiodurans is an extremophile which shows unparalleled resistance to ionizing radiation and oxidative stress. It has a strong mechanism to protect its proteome from oxidative damage.

Protein nanoparticle electrostatic interaction: size dependent counterions induced conformational change of hen egg white lysozyme.

In our earlier paper (Ghosh et al., 2013), we have shown that (i) the positively charged hen egg white lysozyme (HEWL), dispersed in water, binds electrostatically with the negatively functionalized iron oxide nanoparticles (IONPs), and (ii) the Na(+) counterions, associated with functionalized IONPs, diffuse into bound proteins and irreversibly unfold them. Having this information, we have extended our investigation and report here the effect of the size and the charge of alkaline metal counterions on the conformational modification of HEWL.

Rheology of Indian Honey: Effect of Temperature and Gamma Radiation.

Honey brands commonly available in Indian market were characterized for their rheological and thermal properties. Viscosity of all the honey samples belonging to different commercial brands was found to decrease with increase in temperature (5-40°C) and their sensitivity towards temperature varied significantly as explained by calculating activation energy based on Arrhenius model and ranged from 54.0 to 89.

Counter ion induced irreversible denaturation of hen egg white lysozyme upon electrostatic interaction with iron oxide nanoparticles: a predicted model.

The effects of electrostatic interaction between the hen egg white lysozyme (HEWL) and the functionalized iron oxide nanoparticles (IONPs) have been investigated using several techniques, e.g., CD, DSC, ζ-potential, UV-visible spectroscopy, DLS, TEM.

NMR insights into folding and self-association of Plasmodium falciparum P2.

The eukaryotic 60S-ribosomal stalk is composed of acidic ribosomal proteins (P1 and P2) and neutral protein P0, which are thought to be associated as a pentameric structure, [2P1, 2P2, P0]. Plasmodium falciparum P2 (PfP2) appears to play additional non-ribosomal functions associated with its tendency for homo-oligomerization. Recombinant bacterially expressed PfP2 protein also undergoes self-association, as shown by SDS-PAGE analysis and light scattering studies.

Lecithin-based novel cationic nanocarriers (LeciPlex) I: fabrication, characterization and evaluation.

Aims: In the present investigation, the feasibility of fabricating novel self-assembled cationic nanocarriers (LeciPlex) containing cetyltrimethylammonium bromide (CTAB) or didodecyldimethylammonium bromide (DDAB) and soybean lecithin using pharmaceutically acceptable biocompatible solvents such as 2-Pyrrolidone (Soluphor P) and diethyleneglycol monoethyl ether (Transcutol) was established.

Materials & Methods: The interaction between DDAB/CTAB and soybean lecithin in the nanocarriers was confirmed by differential scanning calorimetry and in vitro antimicrobial studies. The positive charge on the nanocarriers was confirmed by zeta potential analysis.

Immunological effects and membrane interactions of chitosan nanoparticles.

The objective of this study was to investigate the in vitro and in vivo effects of blank chitosan nanoparticles on various molecular markers such as nitric oxide (NO) production, IL-6 gene expression, and lymphocyte proliferation involved in the wound healing process. In addition, the membrane effects of chitosan nanoparticles were evaluated using phospholipid vesicles as a model membrane. Peripheral blood mononuclear cells (PBMC) were treated with blank chitosan nanoparticles, and the effect on NO production, IL-6 gene expression, and lymphocyte proliferation was evaluated.

Interaction of propyl paraben with dipalmitoyl phosphatidylcholine bilayer: a differential scanning calorimetry and nuclear magnetic resonance study.

The influence of the preservative, propyl paraben (PPB) on the biophysical properties of dipalmitoyl phosphatidyl choline (DPPC) vesicles, both in multilamellar vesicle (MLV) and unilamellar vesicle (ULV) forms, has been studied using DSC and ((1)H and (31)P) NMR. The mechanism by which PPB interacts with DPPC bilayers was found to be independent of the morphological organization of the lipid bilayer. Incorporation of PPB in DPPC vesicles causes a significant depression in the transition temperature and enthalpy of both the pre-transition (PT) and the gel to liquid crystalline transition.

Effect of propyl paraben on the dipalmitoyl phosphatidic acid vesicles.

The effect of the preservative propyl paraben (PPB) on the phase transition and dynamics of dipalmitoyl phosphatidic acid (DPPA)-buffer (pH 7.4/9.3) vesicles has been studied using DSC and ((1)H and (31)P) NMR.

Nuclear magnetic resonance and thermal studies on the interaction between salicylic acid and model membranes.

DSC and (1H and 31P) NMR measurements are used to investigate the perturbation caused by the keratolytic drug, salicylic acid (SA) on the physicochemical properties of the model membranes. Model membranes (in unilamellar vesicular (ULV) form) in the present studies are prepared with the phospholipids, dipalmitoyl phosphatidylcholine (DPPC), dipalmitoyl phosphatidylethanolamine (DPPE), dipalmitoyl phosphatidic acid (DPPA) and mixed lipid DPPC-DPPE (with weight ratio, 2.5:2.

Salicylic acid-induced effects in the mixed-lipid (dipalmitoyl phosphatidylcholine-dipalmitoyl phosphatidylethanolamine) model membrane.

The effect of the keratolytic drug salicylic acid (SA) on the thermotropic properties and fluidity of the mixed lipid membrane dipalmitoyl phosphatidylcholine (DPPC)-dipalmitoyl phosphatidylethanolamine (DPPE) had been studied using DSC, (1H and 31P) NMR, SAXS, and dynamic light scattering. The membrane was in multilamellar vesicular (MLV) and unilamellar vesicular (ULV) form with SA/(DPPC+DPPE) molar ratios, R(m), in the range from 0 to 0.5.