Light-controlled shape-changing azomacrocycles exhibiting reversible modulation of pyrene fluorescence emission.

We report the design, synthesis, and study of light-induced shape-changing azomacrocycles. These systems have been incorporated with azobenzene photoswitches using alkoxy tethers and triazole units to afford flexibility and binding. We envision that such azomacrocycles are capable of reversibly binding with the guest molecule.

A Major Shell Protein of 1,2-Propanediol Utilization Microcompartment Conserves the Activity of Its Signature Enzyme at Higher Temperatures.

A classic example of an all-protein natural nano-bioreactor, the bacterial microcompartment is a prokaryotic organelle that confines enzymes in a small volume enveloped by an outer protein shell. These protein compartments metabolize specific organic molecules, allowing bacteria to survive in restricted nutrient environments. In this work, 1,2-propanediol utilization microcompartment (PduMCP) was used as a model to study the effect of molecular confinement on the stability and catalytic activity of native enzymes in the microcompartment.

Varying protein architectures in 3-dimensions for scaffolding and modulating properties of catalytic gold nanoparticles.

Fabrication and development of nanoscale materials with tunable structural and functional properties require a dynamic arrangement of nanoparticles on architectural templates. The function of nanoparticles not only depends on the property of the nanoparticles but also on their spatial orientations. Proteins with self-assembling properties which can be genetically engineered to varying architectural designs for scaffolds can be used to develop different orientations of nanoparticles in three dimensions.

Protein morphology drives the structure and catalytic activity of bio-inorganic hybrids.

Bio-hybrid materials have received a lot of attention in view of their bio-mimicking nature. One such biomimetic material with catalytic activity are the protein derived floral nanohybrid. Copper phosphate coordinated flakes can be curated to distinct floral morphology using proteins.

Weakening of interaction networks with aging in tip-link protein induces hearing loss.

Age-related hearing loss (ARHL) is a common condition in humans marking the gradual decrease in hearing with age. Perturbations in the tip-link protein cadherin-23 that absorbs the mechanical tension from sound and maintains the integrity of hearing is associated with ARHL. Here, in search of molecular origins for ARHL, we dissect the conformational behavior of cadherin-23 along with the mutant S47P that progresses the hearing loss drastically.

Probe into a multi-protein prokaryotic organelle using thermal scanning assay reveals distinct properties of the core and the shell.

Background: Bacterial microcompartments represent the only reported category of prokaryotic organelles that are capable of functioning as independent bioreactors. In this organelle, a biochemical pathway with all the enzyme machinery is encapsulated within an all protein shell. The shell proteins and the enzymes have distinct structural features.

Mechanistic insights into surface contribution towards heat transfer in a nanofluid.

Nanofluids play a very important role in thermal management and heat exchange processes and for a stable nanofluid, a surfactant is a salient material. There are many contrasting reports on the thermal conductivity of nanofluids and the associated heat transport mechanism in nanofluids. In this article, four different types of nanoparticles are synthesized using citric acid and oleic acid as surfactants, followed by the assessment of their thermal conductivities.

Functional protein shells fabricated from the self-assembling protein sheets of prokaryotic organelles.

Fabricating protein compartments from protein units is challenging and limited by the use of external stimuli and crosslinkers. Here we explore the fabrication of all-protein compartments using self-assembled proteins of prokaryotic organelles. These proteins have intrinsic interacting domains which are ionic in nature, and spontaneously self-assemble into sheets when over-expressed.

The Wrappers of the 1,2-Propanediol Utilization Bacterial Microcompartments.

The propanediol utilization bacterial microcompartments are specialized protein-based organelles in Salmonella that facilitate the catabolism of 1,2-propanediol when available as the sole carbon source. This smart prokaryotic cell organelle compartmentalizes essential enzymes and substrates in a volume of a few attoliters compared to the femtoliter volume of a bacterial cell thereby enhancing the enzyme kinetics and properly orchestrating the downstream pathways. A shell or coat, which is composed of a few thousand protein subunits, wraps a chain of consecutively acting enzymes and serves as ducts for the diffusion of substrates, cofactors, and products into and out of the core of the microcompartment.

Cellulose-metallothionein matrix for metal binding.

In this report, we have modified bacterial cellulose to a metal binding matrix by covalently conjugating physiological metal chelators known as metallothioneins. The hydroxyl groups of the native bacterial cellulose from Gluconobacter xylinus are epoxidized, followed by the covalent conjugation with the amine groups of the proteins. For the first time, a covalent conjugation of protein with bacterial cellulose is achieved using the epoxy-amine conjugation chemistry.

Role of P-Glycoprotein Inhibitors in the Bioavailability Enhancement of Solid Dispersion of Darunavir.

Objective: The aim of the present study was to improve bioavailability of an important antiretroviral drug, Darunavir (DRV), which has low water solubility and poor intestinal absorption through solid dispersion (SD) approach incorporating polymer with P-glycoprotein inhibitory potential.

Methods: A statistical approach where design of experiment (DoE) was used to prepare SD of DRV with incorporation of P-glycoprotein inhibitors. Using DoE, different methods of preparation, like melt, solvent evaporation, and spray drying method, utilizing carriers like Kolliphor TPGS and Soluplus were evaluated.

Brain delivery of buspirone hydrochloride chitosan nanoparticles for the treatment of general anxiety disorder.

The present work discusses the preparation, characterization and in vivo evaluation of thiolated chitosan nanoparticles (TCS-NPs) of buspirone hydrochloride (BUH) for brain delivery through intranasal route. TCS NPs were prepared by ionic gelation method and characterized for various parameters. The NPs formed were having particle size of 226.