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Graphical abstract Highlights • The chitosan-carbon nanotube hybrid was prepared by homogenizer easily. • And chitosan-carbon nanotube hybrid was applied for sensing the glucose electrochemically. • The electrochemical performance of glucose was characterized by cyclic voltammetry. Abstract In glucose sensors, the direct electron transfer (DET) method delivers electrons from glucose oxidase (GOx) to an electrode without the intervention of a mediator. Many researchers have developed the DET method using carbon nanotube (CNT)-based composites for the permeation into the enzyme co-factor. We synthesized chitosan (Chit) core-shelled CNTs that were hydrophilic, biocompatible, and easily prepared. Electrodes with three different Chit-CNT weight ratios were prepared, and their morphological and physicochemical properties were characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), scanning electron microscopy (SEM), and transition electron microscopy (TEM). The Chit-CNT85 composite (85 wt% Chit) performed optimally by cyclic voltammetry (CV), and was covalently modified with GOx via a routine coupling protocol to form the GOx-Chit-CNT85/ITO electrode. This electrode was electrochemically characterized by impedance spectroscopy (EIS). The GOx loading and pH were optimized against the CV redox potential. The electrode exhibited a fast electron-transfer constant (k s) of 8.2 s−1. The cathodic peak of GOx decreased in response to increasing glucose concentrations, but no changes were observed in the presence of physiological interfering substances such as ascorbic acid and uric acid. Therefore, our GOx-Chit-CNT85/ITO electrode has the potential for use in glucose sensing directly without a mediator. [ABSTRACT FROM AUTHOR]

PELP1 (proline-, glutamic acid-, and leucine-rich protein 1) has been recognized as a coactivator of estrogen receptor (ER)-recruiting p300/CREB-binding protein histone acetyltransferase to the target chromosome. The present study shows that PELP1 does indeed coactivate ER-mediated transcription but also serves as a corepressor of other nuclear hormone receptors (NR)- and non-NR sequence-specific transcription factors tested, including GR, Nut77, AP1, NF-κB, and TCF/SRF. PELP1 expression also retarded the proliferation of mouse fibroblast cell lines in which there was no detectable ER. This was due, at least in part, to the suppressed activation of serum-response genes such as c-fos that in turn resulted from the blocked histone hyperacetylation of nucleosomes containing the c-fos promoter region. The N-terminal leucine-abundant region of PELP1 was observed to interact with HDAC2 and exhibited repressive activity when tethered to the chromatin. In addition, the C-terminal glutamic acid-abundant region bound to the hypoacetylated histones H3 and H4 and prevented them from becoming substrates of histone acetyltransferase. Thus PELP1 promotes and maintains the hypoacetylated state of histones at the target genomic site, and ER binding reverses its role to hyperacetylate histones through an as yet unidentified mechanism. [ABSTRACT FROM AUTHOR]

Direct electron transfer (DET) glucose sensors are third-generation biosensors, which allow the enzyme to directly transfer electrons by glucose oxidation without a mediator. In previous studies, many researchers have focused on the glucose oxidase (GOx)-based DET glucose sensor; however, an efficient DET glucose sensor using flavin adenine dinucleotide (FAD)-glucose dehydrogenase (GDH) has not been developed. In the present study, we bound FAD-GDH and multi-walled carbon nanotubes (MWCNT), using chitosan (CS) compounds that support hydrogen bonding, van der Waals forces, and 3D structural adsorption. The GDH/CS-MWCNT-5 composite, which had a GDH concentration of 75 wt%, was physically adsorbed on screen-printed carbon electrodes (SPCEs), and cyclic voltammetry indicated that its oxidation and reduction peaks were at − 0.422 V and − 0.543 V (vs Ag/AgCl), respectively. In addition, the electrochemical results confirmed that the prepared GDH/CS-MWCNT/SPCEs were not affected by other interfering substances or oxygen at pH of 7. The GDH/CS-MWCNT/SPCEs displayed oxidation catalytic currents, which increased according to glucose concentrations across a range of 0–5.5 mM. Finally, the short-term stability of glucose, assessed for 10 days, was maintained at 80% of the GDH enzyme activity for 6 days, and it reduced to 50% of the initial activity for the remaining 4 days. Here, we illustrate the potential utility of the FAD-GDH-based DET method in continuous glucose monitoring sensors. Diagram of the GDH/CS-MWCNT fabrication process and glucose sensing [Display omitted] • CS-MWCNTs were conjugated with FAD-GDH by hydrogen bonding. • CS-MWCNTs were optimized with GDH for DET glucose sensing. • GDH/CS-MWCNT showed good response with glucose under interfering substances. [ABSTRACT FROM AUTHOR]

Abstract: We have screened 356 libraries of Korean herbal plant extracts to find potential anti-obesity drugs. We employed the recently developed fluorescence polarization high throughput screening (FP HTS) assays of human neuropeptide FF (NPFF) receptors in 384-well microtiter plates. The primary hits were cherry-picked from the libraries and further analyzed by secondary displacement curve assays, in vitro GTPγS binding assays and cell-based CRE luciferase reporter assays. Agonists of NPFF receptors showed biphasic affinity curves while the antagonist, BIBP 3226, gave a monophasic affinity curve in competitive binding assays. We isolated and characterized two agonists of human NPFF2 receptor, PC 314 with K i of 1.42μM, and PC 315 with K i of 2.17μM from Schizandra chinensis. PC 314 and PC 315 have been characterized as benzoylgomisin Q (M.W. 552) and gomisin G (M.W. 536). We report that PC 314 and PC 315 are the first non-peptide, natural compounds, which bind to human NPFF2 receptors with good affinity. PC 314 and PC 315 inhibit forskolin-stimulated luciferase expression when CHO cells are co-transfected with NPFF2 receptor and CRE reporter vector. They possess the pharmacological and functional profiles of full agonists. The FP HTS system provides a specific, sensitive and reproducible methodology for studying and screening NPFF receptor ligands. [Copyright &y& Elsevier]

(A) Schematic illustration and SEM and TEM images of CS-shell/MWCNT-core nanohybrids structure. (B) Photograph of commercial alumina-based humidity sensor electrode. (C) Photograph of the humidity sensor electrode coated by CS-MWCNT nanohybrids and SEM image showing electrodes interconnected by CS-MWCNT nanohybrids. • Fabrication of chitosan-MWCNT core–shell-structured nanohybrid (CS-MWCNT) on a gold electrode as an electrochemical humidity sensor. • CS-MWCNT nanohybrid fibers exhibiting low resistance without moisture. • Remarkable results in the humidity response with an efficient humidity sensing range of 30–90%. Multi-walled carbon nanotubes (MWCNTs) were fabricated on a gold electrode to develop a resistance-sensing humidity sensor with low resistance. Core-shell-structured nanohybrids were prepared using Chitosan-MWCNT to obtain good hydrophilicity, resulting in a highly responsive humidity sensor. We also measured resistance, which changes due to hydrogen bonding between the amine group of chitosan and H 2 O. The structure of the fabricated chitosan-MWCNT core–shell-structured nanohybrid was measured. Furthermore, we determined the highest response and linearity of the CS-MWCNT25 nanohybrids based on the number of coats on the electrode and the composition ratio of chitosan and MWCNTs. The fabricated CS-MWCNT25 nanohybrid humidity sensor exhibited good electrical efficiency without voltage or frequency dependence and a low-temperature dependency with a temperature coefficient (RH/°C) of 0.187%. Finally, a fast recovery time of 40 s between 30% and 100% RH, a maximum humidity hysteresis of less than 0.300 ± 0.001%, and long-term stability for 2 months indicated that this is an excellent humidity sensor. [ABSTRACT FROM AUTHOR]