Photo-switchable microbial fuel-cells.

Regulation of Bio-systems in a clean, simple, and efficient way is important for the design of smart bio-interfaces and bioelectronic devices. Light as a non-invasive mean to control the activity of a protein enables spatial and temporal control far superior to other chemical and physical methods. The ability to regulate the activity of a catalytic enzyme in a biofuel-cell reduces the waste of resources and energy and turns the fuel-cell into a smart and more efficient device for power generation.

Human CCL5 trimer: expression, purification and initial crystallographic studies.

The chemokine CCL5 is considered to be a potential therapeutic target because of its ability to recruit immune cells to inflammatory sites. CCL5 aggregates under physiological conditions, and high-order oligomer formation is considered to be significant for cell migration, immune-cell activation and HIV cell entry. The structure of the high-order oligomer is unknown and the mechanism by which the oligomer is derived has yet to be established.

Bidirectional motility of kinesin-5 motor proteins: structural determinants, cumulative functions and physiological roles.

Mitotic kinesin-5 bipolar motor proteins perform essential functions in mitotic spindle dynamics by crosslinking and sliding antiparallel microtubules (MTs) apart within the mitotic spindle. Two recent studies have indicated that single molecules of Cin8, the Saccharomyces cerevisiae kinesin-5 homolog, are minus end-directed when moving on single MTs, yet switch directionality under certain experimental conditions (Gerson-Gurwitz et al., EMBO J 30:4942-4954, 2011; Roostalu et al.

The importance of the helical structure of a MamC-derived magnetite-interacting peptide for its function in magnetite formation.

Biomineralization is the process of mineral formation by organisms and involves the uptake of ions from the environment in order to produce minerals, with the process generally being mediated by proteins. Most proteins that are involved in mineral interactions are predicted to contain disordered regions containing large numbers of negatively charged amino acids. Magnetotactic bacteria, which are used as a model system for iron biomineralization, are Gram-negative bacteria that can navigate through geomagnetic fields using a specific organelle, the magnetosome.

Noise-induced drift in two-dimensional anisotropic systems.

We study the isothermal Brownian dynamics of a particle in a system with spatially varying diffusivity. Due to the heterogeneity of the system, the particle's mean displacement does not vanish even if it does not experience any physical force. This phenomenon has been termed "noise-induced drift," and has been extensively studied for one-dimensional systems.

Electrophoretic deposition of single-source precursors as a general approach for the formation of hybrid nanorod array heterostructures.

Hypothesis: Subjecting colloids to electric fields often results in (electrophoretic) deposition on conductive substrates. Dispersing a single-source precursor (SSP) of choice in an appropriate solvent, should allow its deposition on different substrates. The SSP-solvent interaction might play a role in the deposition (e.

DNA bipedal motor walking dynamics: an experimental and theoretical study of the dependency on step size.

We present a detailed coarse-grained computer simulation and single molecule fluorescence study of the walking dynamics and mechanism of a DNA bipedal motor striding on a DNA origami. In particular, we study the dependency of the walking efficiency and stepping kinetics on step size. The simulations accurately capture and explain three different experimental observations.

Topological quantization of energy transport in micro- and nano-mechanical lattices.

Topological effects typically discussed in the context of quantum physics are emerging as one of the central paradigms of physics. Here, we demonstrate the role of topology in energy transport through dimerized micro- and nano-mechanical lattices in the classical regime, i.e.

Photoconductance from Exciton Binding in Molecular Junctions.

We report on a theoretical analysis and experimental verification of a mechanism for photoconductance, the change in conductance upon illumination, in symmetric single-molecule junctions. We demonstrate that photoconductance at resonant illumination arises due to the Coulomb interaction between the electrons and holes in the molecular bridge, so-called exciton-binding. Using a scanning tunneling microscopy break junction technique, we measure the conductance histograms of perylene tetracarboxylic diimide (PTCDI) molecules attached to Au-electrodes, in the dark and under illumination, and show a significant and reversible change in conductance, as expected from the theory.

Negatively charged polypeptide-peptide nanoparticles showing efficient drug delivery to the mitochondria.

Polymeric nanoparticles (NPs) represent an effective platform for drug delivery systems, albeit with various limitations including low drug loading capacity, cytotoxicity and specificity. NPs composed of the negatively charged Polypeptide, poly gamma glutamic acid (γ-PGA) and a designed amphiphilic and cationic β-sheet Peptide (denoted PoP-NPs) loaded with the drug lonidamine (LND), denoted LND-PoP-NPs were previously used in our lab to successfully target the mitochondria when coated with the peptide (LND-mPoP-NPs). In this study, we improved the drug capacity of the LND-mPoP-NPs in addition to lowering non-specific toxicity associated with the drug deficient mPoP-NPs.

Transition metal binding selectivity in proteins and its correlation with the phylogenomic classification of the cation diffusion facilitator protein family.

Divalent d-block metal cations (DDMCs), such as Fe, Zn and Mn, participate in many biological processes. Understanding how specific DDMCs are transported to and within the cell and what controls their binding selectivity to different proteins is crucial for defining the mechanisms of metalloproteins. To better understand such processes, we scanned the RCSB Protein Data Bank, performed a de novo structural-based comprehensive analysis of seven DDMCs and found their amino acid binding and coordination geometry propensities.

A General Synthesis of Porous Carbon Nitride Films with Tunable Surface Area and Photophysical Properties.

Graphitic carbon nitride (g-CN) has emerged as a promising material for energy-related applications. However, exploitation of g-CN in practical devices is still limited owing to difficulties in fabricating g-CN films with adjustable properties and high surface area. A general and simple pathway is reported to grow highly porous and large-scale g-CN films with controllable chemical and photophysical properties on various substrates using the doctor blade technique.

Periostin in cardiovascular disease and development: a tale of two distinct roles.

Tissue development and homeostasis are dependent upon the concerted synthesis, maintenance, and degradation of extracellular matrix (ECM) molecules. Cardiac fibrosis is now recognized as a primary contributor to incidence of heart failure, particularly heart failure with preserved ejection fraction, wherein cardiac filling in diastole is compromised. Periostin is a cell-associated protein involved in cell fate determination, proliferation, tumorigenesis, and inflammatory responses.

A quantitative assessment of the membrane-integral sub-proteome of a bacterial magnetic organelle.

Unlabelled: Magnetotactic bacteria produce chains of complex membrane-bound organelles that direct the biomineralization of magnetic nanoparticles and serve for magnetic field navigation. These magnetosome compartments have recently emerged as a model for studying the subcellular organization of prokaryotic organelles. Previous studies indicated the presence of specific proteins with various functions in magnetosome biosynthesis.

Ternary hybrid nanostructures of Au-CdS-ZnO grown via a solution-liquid-solid route using Au-ZnO catalysts.

Multi-component nanostructures of Au-CdS-ZnO with a novel morphology were synthesized by a non-conventional strategy where seeded growth is combined with solution-liquid-solid (SLS) growth. Each of these synthetic routes is used for growing a different domain of the final heterostructure, where ZnO rods are grown first on Au nanoparticles via heterogeneous nucleation while CdS is later grown between these two domains via SLS, using the Au tip of the preformed Au-ZnO as a catalyst. The in situ alloying of the Au tip with Cd enabled the metal tip to function as an SLS catalyst at a relatively mild reaction temperature which is lower than the melting point of pure Au.

High-speed Continuous-wave Stimulated Brillouin Scattering Spectrometer for Material Analysis.

Recent years have witnessed a significant increase in the use of spontaneous Brillouin spectrometers for non-contact analysis of soft matter, such as aqueous solutions and biomaterials, with fast acquisition times. Here, we discuss the assembly and operation of a Brillouin spectrometer that uses stimulated Brillouin scattering (SBS) to measure stimulated Brillouin gain (SBG) spectra of water and lipid emulsion-based tissue-like samples in transmission mode with <10 MHz spectral-resolution and <35 MHz Brillouin-shift measurement precision at <100 ms. The spectrometer consists of two nearly counter-propagating continuous-wave (CW) narrow-linewidth lasers at 780 nm whose frequency detuning is scanned through the material Brillouin shift.

GalNAc bio-functionalization of nanoparticles assembled by electrostatic interactions improves siRNA targeting to the liver.

RNA interference (RNAi) has the potential to reversibly silence any gene with high efficiency and specificity. To fulfill the clinical potential of RNAi, delivery vehicles are required to transport the short interfering RNA (siRNA) to the site of action in the cells of target tissues. Here, we describe the features of novel liver-targeted siRNA nanoparticles (NPs), co-assembled due to the complexation of alginate sulfate (AlgS) with siRNA, mediated by calcium ions bridges (AlgS-Ca-siRNA NPs) and then bioconjugation of a targeting ligand onto the AlgS upon the NP surface.

Highly Efficient Flavin-Adenine Dinucleotide Glucose Dehydrogenase Fused to a Minimal Cytochrome C Domain.

Flavin-adenine dinucleotide (FAD) dependent glucose dehydrogenase (GDH) is a thermostable, oxygen insensitive redox enzyme used in bioelectrochemical applications. The FAD cofactor of the enzyme is buried within the proteinaceous matrix of the enzyme, which makes it almost unreachable for a direct communication with an electrode. In this study, FAD dependent glucose dehydrogenase was fused to a natural minimal cytochrome domain in its c-terminus to achieve direct electron transfer.

Two Distinct Polymorphic Folding States of Self-Assembly of the Non-amyloid-β Component Differ in the Arrangement of the Residues.

Parkinson's disease is a degenerative disorder of the central nervous system. It is characterized by presence of Lewy bodies (LBs), in which the main components of the LBs are α-synuclein (AS) aggregates. The central domain of AS, known as the "non-amyloid-β component" (NAC) is responsible for the aggregation properties of AS.

One-Pot Synthesis of Nickel-Modified Carbon Nitride Layers Toward Efficient Photoelectrochemical Cells.

A new method to significantly enhance the photoelectrochemical properties of phenyl-modified carbon nitride layers via the insertion of nickel ions into carbon nitride layers is reported. The nickel ions are embedded within the carbon nitride layers by manipulating the interaction of Ni ions and molten organic molecules at elevated temperature prior to their condensation. A detailed analysis of the chemical and photophysical properties suggests that the nickel ions dissolve in the molten molecules, leading to the homogeneous distribution of nickel atoms within the carbon nitride layers.

Curcumin Protects Skin against UVB-Induced Cytotoxicity via the Keap1-Nrf2 Pathway: The Use of a Microemulsion Delivery System.

Curcumin was found to be beneficial in treating several skin pathologies and diseases, providing antioxidant protection due to its reducing properties and its electrophilic properties (the ability to activate the Nrf pathway and induce phase II cytoprotective enzymes). Nevertheless, clinical applications of curcumin are being hampered by its insufficient solubility, chemical instability, and poor absorption, leading to low efficacy in preventing skin pathologies. These limitations can be overcome by using a nanotechnology-based delivery system.

Insight into a New Binding Site of Zinc Ions in Fibrillar Amylin.

Amylin peptides are secreted together with insulin and zinc ions from pancreatic β-cells. Under unknown conditions, the amylin peptides aggregate to produce oligomers and fibrils, and in some cases Zn ions can bind to amylin peptides to form Zn-aggregate complexes. Consequently, these aggregates lead to the death of the β-cells and a decrease in insulin, which is one of the symptoms of type-2 diabetes (T2D).

The Electrosome: A Surface-Displayed Enzymatic Cascade in a Biofuel Cell's Anode and a High-Density Surface-Displayed Biocathodic Enzyme.

The limitation of surface-display systems in biofuel cells to a single redox enzyme is a major drawback of hybrid biofuel cells, resulting in a low copy-number of enzymes per yeast cell and a limitation in displaying enzymatic cascades. Here we present the electrosome, a novel surface-display system based on the specific interaction between the cellulosomal scaffoldin protein and a cascade of redox enzymes that allows multiple electron-release by fuel oxidation. The electrosome is composed of two compartments: (i) a hybrid anode, which consists of dockerin-containing enzymes attached specifically to cohesin sites in the scaffoldin to assemble an ethanol oxidation cascade, and (ii) a hybrid cathode, which consists of a dockerin-containing oxygen-reducing enzyme attached in multiple copies to the cohesin-bearing scaffoldin.

Surface Analysis of Nanocomplexes by X-ray Photoelectron Spectroscopy (XPS).

Self-assembled nanocomplexes composed of individual molecules that spontaneously connect via noncovalent interactions have recently emerged as versatile alternatives to conventional controlled drug delivery systems because of their unique bioinspired properties (responsiveness, dynamics, etc.). Characterization of such nanocomplexes typically includes their size distribution, surface charge, morphology, drug entrapment efficiency, and verification of the coexistence of labeled components within the nanocomplexes using a colocalization study.

A New Solid Solution Approach for the Study of Self-Irradiating Damage in non-Radioactive Materials.

A new method to produce a model system for the study of radiation damage in non-radioactive materials is presented. The method is based on homogenously dissolving minute amounts of Th ions in thin films in a controllable manner using a small volume chemical bath deposition technique. This approach is demonstrated for PbS films.