• Mahmoud Locklear posted an update 4 days, 3 hours ago

    ConspectusThe cell plasma membrane (PM) contains thousands of proteins that sense and respond to the outside environment. These proteins have evolved sensitivity to a wide variety of physical and chemical signals and act as a delivery system across the PM. Membrane proteins are critical for information flow and decision making in the cell and thus are important targets in drug development. A critical aspect of membrane protein function is the way they interact with other proteins, often through the formation of dimers or small oligomers that regulate function at the protein, cell, and organism levels. Resolving membrane protein interactions in a live cell environment is challenging because of the chemical diversity and spatial heterogeneity of the PM. In this Account, we describe a fluorescence technique called pulsed interleaved excitation fluorescence cross-correlation spectroscopy (PIE-FCCS) that is ideally suited to quantify membrane associations in live cells. PIE-FCCS is a two-color fluorescence fluctuay regulates the catalytic activity of the kinase, but higher order oligomerization and ligand-independent dimerization can complicate this historically simple paradigm. PIE-FCCS data have resolved a low population of EGFR dimers under basal conditions and assembly into multimers when stimulated with ligand. While GPCRs function primarily as monomers, dimerization has been hypothesized to regulate function for some receptors. PIE-FCCS data have established the dimerization potential of rhodopsin at low densities and were critical for the discovery of a novel dimerization interface in human cone opsins. This Account describes the how FCCS and PIE-FCCS can reveal the details of quaternary interactions in each of these receptor systems.Bladder cancer is a complex and highly prevalent disease associated with substantial morbidity and mortality rates. Detection and surveillance of biomarkers for bladder cancer are particularly critical in clinical diagnosis and prognostic monitoring. The current detection methods are limited to low sensitivity, low throughput, and high operational cost. NIK SMI1 In this paper, we present a multiplexed detection strategy for microRNA (miRNA) related to bladder cancer by utilizing photonic crystal (PhC) barcodes. PhC barcodes have characteristic reflective peaks generated by periodic orderly porous nanostructures, providing an ideal choice for encoding element. Besides, owing to the larger surface area provided by the structure, PhC barcodes is an effective platform for probes ligation and miRNAs detection. Compared with the planar microarrays, PhC barcodes avoid the problem of steric hindrance, making it express more efficient reaction and higher detection sensitivity. By introducing hybridization chain reaction (HCR), the detection efficiency of this strategy is greatly improved, making the rapid, accurate, high sensitivity quantification of miRNAs possible. The results indicated that the multiplexed detection strategy based on PhC barcodes can be applied to the clinical analysis of tumor markers.Despite the generally hostile nature of the environments involved, chemistry does occur in space. Molecules are seen in environments that span a wide range of physical and chemical conditions and that clearly were created by a multitude of chemical processes, many of which differ substantially from those associated with traditional equilibrium chemistry. The wide range of environmental conditions and processes involved with chemistry in space yields complex populations of materials, and because the elements H, C, O, and N are among the most abundant in the universe, many of these are organic in nature, including some of direct astrobiological interest. Much of this chemistry occurs in “dense” interstellar clouds and protostellar disks surrounding forming stars because these environments have higher relative densities and more benign radiation fields than in stellar ejectae or the diffuse interstellar medium. Because these are the environments in which new planetary systems form, some of the chemical species made in these environments are expected to be delivered to the surfaces of planets where they can potentially play key roles in the origin of life. Because these chemical processes are universal and should occur in these environments wherever they are found, this implies that some of the starting materials for life are likely to be widely distributed throughout the universe.Sulfoxaflor, a sulfoximine insecticide, could efficiently control many insect pests of sap-feeding. Microbial degradation of sulfoxaflor and the enzymatic mechanism involved have not been studied to date. A bacterial isolate JW2 that transforms sulfoxaflor to X11719474 was isolated and identified as Aminobacter sp. CGMCC 1.17253. Both the recombinant Escherichia coli strain harboring the Aminobacter sp. CGMCC 1.17253 nitrile hydratase (NHase) gene and the pure NHase acquired sulfoxaflor-degrading ability. Aminobacter sp. CGMCC 1.17253 NHase is a typical cobalt-containing NHase content of subunit α, subunit β, and an accessory protein, and the three-dimensional homology model of NHase was built. Substrate specificity tests showed that NHase catalyzed the conversion of acetamiprid, thiacloprid, indolyl-3-acetonitrile, 3-cyanopyridine, and benzonitrile into their corresponding amides, indicating its broad substrate specificity. This is the first report of the pure bacteria degradation of the sulfoxaflor residual in the environment and reveals the enzymatic mechanism mediated by Aminobacter sp. CGMCC 1.17253.The rise of environmental and health concerns due to the excessive use of the conventional fungicide urges the search for sustainable alternatives of agronanofungicides where the latter is aimed to enhance plant uptake and minimize the volatilization, leaching, and runoff of fungicides. With this in mind, fungicides of hexaconazole and/or dazomet were encapsulated into chitosan nanoparticles for the formulation of chitosan-based agronanofungicides. In the present study, chitosan nanoparticles (2 nm), chitosan-hexaconazole nanoparticles (18 and 168 nm), chitosan-dazomet nanoparticles (7 and 32 nm), and chitosan-hexaconazole-dazomet nanoparticles (5 and 58 nm) were synthesized and used as potent antifungal agents in combating the basal stem rot (BSR) disease caused by Ganoderma boninense in which they were evaluated via an artificial inoculation of oil palm seedlings with the rubber woodblock, which was fully colonized with the fungal Ganoderma boninense mycelium. The results revealed that chitosan nanoparticles could act as dual modes of action, which are themselves as a biocide or as a nanocarrier for the existing fungicides.