Pseudomonas aeruginosa produces an extracellular compound with yellowish green fluorescence, called pyoverdin, which functions as a siderophore. The production of formerly fluorescein, is concomitant the another siderophore, pyochelin. Pyoverdin produced by P. in several forms, some were separated on gel filtration columns and reverse-phase, high-pressure liquid chromatography columns. An active form iron-free pyoverdin was purified to homogeneity. elution from monitored for absorbance,...

The purple phototrophic bacteria synthesize an extensive system of intracytoplasmic membranes (ICM) in order to increase the surface area for absorbing and utilizing solar energy. Rhodobacter sphaeroides cells contain curved membrane invaginations. In study biogenesis ICM this bacterium mature precursor (upper pigmented band - UPB) were purified compared at single level using electron, atomic force fluorescence microscopy, revealing fundamental differences their morphology, protein...

Fluorescent probes are useful in biophysics research to assess the spatial distribution, mobility, and interactions of biomolecules. However, fluorophores can undergo "self-quenching" their fluorescence intensity at high concentrations. A greater understanding concentration-quenching effects is important for avoiding artifacts images relevant energy transfer processes photosynthesis. Here, we show that an electrophoresis technique be used control migration charged associated with supported...

The light-harvesting pigment–protein complex II (LHCII) from plants can be used as a component for biohybrid photovoltaic devices, acting photosensitizer to increase the photocurrent generated when devices are illuminated with sunlight. LHCII is effective at photon absorption in red and blue regions of visible spectrum, however, it has low green region (550–650 nm). Previous studies have shown that synthetic chromophores fill this spectral gap transfer additional energy LHCII, but was...

Abstract The fundamental biophysics of gliding microtubule (MT) motility by surface-tethered kinesin-1 motor proteins has been widely studied, as well applied to capture and transport analytes in bioanalytical microdevices. In these systems, phenomena such molecular wear fracture into shorter MTs have reported due the mechanical forces on MT during transport. present work, we show that can be split longitudinally protofilament bundles (PFBs) work performed surface-bound kinesin motors. We...

Light-Harvesting Complex II (LHCII) is a chlorophyll-protein antenna complex that efficiently absorbs solar energy and transfers electronic excited states to photosystems I II. Under excess light intensity LHCII can adopt photoprotective state in which excitation safely dissipated as heat, process known Non-Photochemical Quenching (NPQ). In vivo NPQ triggered by combinatorial factors including transmembrane ΔpH, PsbS protein LHCII-bound zeaxanthin, leading dramatically shortened fluorescence...

Self-assembled proteoliposomes allow highly efficient energy transfer from the spectrally-complementary chromophore Texas Red to plant light-harvesting protein LHCII, increasing effective absorption range of this bio-hybrid system.

We report generation of modular, artificial light-harvesting assemblies where an amphiphilic diblock copolymer, poly(ethylene oxide)-block-poly(butadiene), serves as the framework for noncovalent organization BODIPY-based energy donor and bacteriochlorin-based acceptor chromophores. The are adaptive form well-defined micelles in aqueous solution high-quality monolayer bilayer films on solid supports, with latter showing greater than 90% transfer efficiency. This study lays groundwork further...

Abstract Supported lipid bilayers have proven effective as model membranes for investigating biophysical processes and in development of sensor array technologies. The ability to modify after their formation situ could greatly advance membrane technologies, but is difficult via current state-of-the-art Here we demonstrate a novel method that allows the controlled post-formation processing modification complex supported bilayer arrangements, under aqueous conditions. We exploit...

The Light-Harvesting (LH) pigment-protein complexes found in photosynthetic organisms have the role of absorbing solar energy with high efficiency and transferring it to reaction centre complexes. LH contain a suite pigments that each absorb light at specific wavelengths, however, natural combinations within any one protein complex do not cover full range radiation. Here, we provide an in-depth comparison relative effectiveness five different organic "dye" molecules (Texas Red, ATTO, Cy7,...

Natural photosynthetic "thylakoid" membranes found in green plants contain a large network of light-harvesting (LH) protein complexes. Rearrangement this machinery, laterally within stacked called "grana", alters protein-protein interactions leading to changes the energy balance system. Preparation an experimentally accessible model system that allows detailed investigation these complex can be achieved by interfacing thylakoid and synthetic lipids into template comprised polymerized 2D...

We characterize the photophysical interactions between lipid-linked chromophores and plant light-harvesting proteins incorporated into nanodiscs using optical spectroscopy, simulations theoretical modelling.

ABSTRACT The temperature‐dependent aggregation and recovery of the copolymer poly(ethylene oxide) 22 ‐ b‐ poly( N ‐isopropylacrylamide) 29 with a C 12 end‐cap in aqueous solutions salts acids are investigated. Salt affected critical temperature manner predictable according to Hofmeister series, kosmotropic adipic ion lowering chaotropic iodide raising it. Also, both increased size aggregates formed heating, due electrostatic shielding aggregated structures provided by electrolytes....

The plant light-harvesting pigment-protein complex LHCII is the major antenna sub-unit of PSII and generally (though not universally) accepted to play a role in photoprotective energy dissipation under high light conditions, process known Non-Photochemical Quenching (NPQ). underlying mechanisms trapping within are still debated. Various models have been proposed for molecular detail NPQ, but they often based on different interpretations very similar transient absorption measurements isolated...

Abstract Nanocomposite membrane assemblies are a class of materials that incorporate inorganic/organic nanoscale materials, such as fullerenes and gold nanoparticles or nanostructured with bio‐inspired amphiphilic structures composed molecules lipids block copolymers. One the intrigues is potential to develop programmable mimic biological complexity, dynamics function. Due nature assemblies, it becomes necessary understand interactions between these resolution. Although many techniques able...

Shiga toxin-producing <i>Escherichia coli</i> (STEC) poses a serious threat to human health through the consumption of contaminated food products, particularly beef and produce. Early detection in chain, discrimination from other non-pathogenic (E. coli), is critical preventing outbreaks, meeting current agricultural screening standards. These pathogens often present low concentrations samples, making discriminatory difficult without use costly, time-consuming methods (e.g. culture). Using...