Selective autophagy regulates chloroplast protein import and promotes plant stress tolerance.

Chloroplasts are plant organelles responsible for photosynthesis and environmental sensing. Most chloroplast proteins are imported from the cytosol through the translocon at the outer envelope membrane of chloroplasts (TOC). Previous work has shown that TOC components are regulated by the ubiquitin-proteasome system (UPS) to control the chloroplast proteome, which is crucial for the organelle's function and plant development. Here, we demonstrate that the TOC apparatus is also subject to K63-linked polyubiquitination and regulation by selective autophagy, potentially promoting plant stress tolerance. We identify NBR1 as a selective autophagy adaptor targeting TOC components, and mediating their relocation into vacuoles for autophagic degradation. Such selective autophagy is shown to control TOC protein levels and chloroplast protein import and to influence photosynthetic activity as well as tolerance to UV-B irradiation and heat stress in Arabidopsis plants. These findings uncover the vital role of selective autophagy in the proteolytic regulation of specific chloroplast proteins, and how dynamic control of chloroplast protein import is critically important for plants to cope with challenging environments.

An electrochemiluminescence immunosensor for myoglobin using an indium tin oxide glass electrode modified with gold nanoparticles and platinum nanowires.

An electrochemiluminescence (ECL) immunosensor was fabricated to detect myoglobin in human serum. Specifically, gold nanoparticles and platinum nanowires were deposited onto indium tin oxide-coated glass with 3-aminopropyl-trimethoxysilane as the linker to fabricate a basal electrode. The gold nanoparticles had a diameter of approximately 5 nm, and the platinum nanowires had diameters of approximately 2-3 nm and lengths on the order of dozens of nanometers. The nanomaterials effectively enhanced the ECL of luminol and enabled it to emit strong light, even in a weakly basic environment. A myoglobin antibody was then covalently immobilized on the electrode. Upon formation of the immunocomplex, the intensity of the luminol ECL was reduced. Under the optimized experimental conditions, the intensity of the ECL linearly decreased with the logarithm of the myoglobin concentration over the range of 3.0 ng·mL-1 to 0.32 µg·mL-1, and the detection limit was 0.11 ng·mL-1. Graphical abstract Schematic of an electrochemiluminescent immunosensor for myoglobin using gold nanoparticles and platinum nanowires as supporting matrix on indium tin oxide coated glass. It can detect myoglobin in human serum with a detection limit of 0.11 ng·mL-1 and high selectivity.

A flower-like ionic molecularly imprinted membrane for the deglycosylation of rutin.

A kind of molecularly imprinted polymer based on ionic liquids (MIPIL) with flower-like shape was developed for the adsorption of rutin and its deglycosylated product. The MIPIL film was characterized by scanning electron microscope (SEM) and X-ray photo-electron spectroscopy (XPS). The adsorption capacity of quercetin on the proposed imprinted cavity of rutin in the presence of glucose and rhamnose was 3.7 ± 0.017 times as much as that in the absence of glucose and rhamnose. And the adsorption capacity of quercetin varied with the concentration of glucose and rhamnose changing. Thus, the proposed MIPIL film coupled with HPLC was used to explore the deglycosylation of rutin by tracking rutin and quercetin, which confirmed to the pseudo-first-order reaction kinetic with the constant of 0.044 ± 1.5 × 10-4 min-1 at 35 °C. The rutin and quercetin were quantified using the above MIPIL film in the two Ginkgo leaves extracted by pure water and pure ethanol, respectively. Because of lower solubility in water, the content of rutin in ethanol extraction solution was higher than in water solution. On the contrary, the content of quercetin in water extraction solution was higher than in ethanol solution, which resulted from the higher solubility of glucose and rhamnose in water. The RSD ranged from 2.8 to 4.5%, and the recovery rate ranged from 91.9 to 105.3%.

A High-matched Melamine Sensor Using Core/shell Nano Particles of Fe3O4@Polyrutin-COOH and Ionic Liquid as Imprinted Polymeric Monomers.

We describe here a magnetic molecular imprinted polymeric ionic liquid (MMIPIL) film by using a functionalized ionic liquid (3-vinyl-4-amino-5-imidazole carboxamide chloride, IL) and Fe3O4@Polyrutin-COOH as a functional monomer and supporting materials. The change in the direction of the charge density in the structure of MMIPIL polymer resulted in a red shift of about 100 nm for the characteristic group of -C=O. Polyrutin containing an electron-rich benzene ring and multiple hydroxyl groups not only prevented the aggregation of Fe3O4, but also benefitted to immobilize template molecules. More symmetric amino groups in the template molecules generated more hydrogen bonds and other synergistic effects between MEL and the functional monomers, which resulted in a highly-matched and highly stable MMIPIL sensor. The proposed magnetic sensor lowered the matching potential, and enhanced the signal for the detection of melamine (MEL) in milk powder. Under the optimum conditions, the MEL template molecule showed a significant linear relationship between 5.0 × 10-3 and 0.8 µg/L with a detection limit (S/N = 3) of 1.5 × 10-3 µg/L. The MMIPIL sensor showed wonderful selectivity and exhibited facile, fast and efficient results in the monitoring MEL with recoveries of between 96.5 and 108.3%.

Clinical Chemistry Route for Investigation of Alzheimer's Disease: A Label-Free Electrochemiluminescent Biosensor for Glycogen Synthase Kinase-3 Beta.

Herein, we report a novel label-free electrochemiluminescent (ECL) biosensor for the detection of glycogen synthase kinase-3 beta (GSK-3ß). A simple and feasible sensor was prepared by a two-step process. A polymeric coordination layer of phosphorylated poly vinyl with Zr4+ was used as the sensory hosting matrix because it efficiently formed a complex. The exterior Zr4+ can further combine with another phosphate through coordination, and GSK-3ß catalyzes the phosphorylation of protein molecules. Thus, the biosensor can detect GSK-3ß using luminol as an ECL probe. The ECL intensity of the proposed sensor responded proportionally to the concentration of GSK-3ß under direct immersion mode with a linear response in a logarithmic scale over the wide range from 0.5 to 91.5 ng L-1 and a detection limit of 0.055 ng L-1. Excellent selectivity, stability, and reproducibility were achieved using the prepared biosensor, which has a simple preparation, low cost, and disposable suitability. This work aims to provide a novel tool for early diagnosis and pathological mechanism exploration about AD by detecting inchoate change of GSK-3ß content in body fluid, thus to precaution the risk of Alzheimer's disease. It is of great importance for clinical chemistry for the investigation of Alzheimer's disease.

A solid ionic Lactate biosensor using doped graphene-like membrane of Au-EVIMC-titania nanotubes-polyaniline.

Herein, a doped graphene-like membrane was designed, which was copolymerized to be a solid ionic biosensor by using titania nanotubes (TiNTs), polyaniline (PANI), EvimCl (1-ethyl-3-vinylimidazolium chloride, EVIMC) and chloroauric acid (HAuCl4). The structure of graphene-like arrangement and the copolymerization mechanism of the film were discussed in detail. Because of the high catalytic property, Lactate could be determined on the membrane catalyzed by lactate dehydrogenase (LDH) containing isocitrate dehydrogenase (NAD+), which was immobilized onto the film by electrostatic attraction. The electrochemical response on the LDH/Au-EVIMC-TiNTs-PANI/ITO was increased by twice than the LDH/TiNTs/PANI/ITO, and exhibited two linear responses within the concentration range from 5.5 × 10-7 M to 5.55 × 10-6 M, and 5.55 × 10-6 M to 3.33 × 10-3 M, with a detection limit of 1.65 × 10-7 M (S / N = 3). The interference study for other common coexistence such as uric acid and hemoglobin revealed that there was no overlapping signal for the detection of Lactate on the biosensor. The developed method proved the most stability in the determination of real blood samples, and the recoveries ranged from 96.7% to 105.8% with a satisfactory result.

Efficacy of thymosin alpha-1 and interferon alpha in treatment of chronic viral hepatitis B: a randomized controlled study.

AIM: To observe the efficiency and safety of thymosin-alpha1 treatment in patients with hepatitis B e antigen (HBeAg) and HBV DNA positive chronic hepatitis. METHODS: Sixty-two patients were randomly divided into groups A and B. The patients in group A received subcutaneous injection of 1.6 mg thymosin-alpha1, twice a week (T-alpha1 group) for six months, and the patients in group B received 5 MU interferon alpha (IFN-alpha) each day for fifteen days, then three times weekly (IFN-alpha group) for six months. The results between two groups treated with and the group untreated with IFN-alpha which was followed up for 12 mo (historical control group consisting of 30 patients) were compared, and three groups were comparable between each other (P>0.05) at baseline (age, sex, clinical history, biochemical, and serological parameters). RESULTS: At the end of treatment, complete response, which was defined as alanine aminotransferase (ALT) normalization and HBV DNA and HBeAg loss, occurred in 9 of 29 (31.0%) patients in the T-alpha1 group and in 15 of 33 (45.5%) patients in the IFN-alpha group (chi2=1.36, P>0.05). After a follow-up period of six months, a complete response was observed in 14 of 29 (48.3%) patients in the T-alpha1 group and in 9 of 33 (27.3%) patients in the IFN-alpha group (chi2=2.93, P>0.05). Compared with the results observed in the historical control (HC) group untreated with IFN-alpha which was followed up for 12 mo, the rate of complete response was significantly higher in IFN-alpha group at the end of therapy (1 of 30 vs 15 of 33, chi2=14.72, P<0.001) and in the T-alpha1 group at the end of follow-up (1 of 30 vs 14 of 29, chi2=15.71, P<0.001). In T-alpha1 and IFN-alpha treatment groups, the area under (the plasma concentration time) curve (AUC) of negative HBV DNA and HBeAg was 34%, 17%, 31% and 19% smaller than that in the HC group. By the end of the follow-up period, the proportions of ALT normalization and negative HBV DNA in the T-alpha1 group were significantly higher than those in the IFN-alpha and HC groups. The odds of ALT normalization and negative HBV DNA at the end of the follow-up was three-fold higher in the T-alpha1 group than in the IFN-alpha group. Unlike IFN-alpha, T-alpha1 was well tolerated by all patients, and no side effects appeared in T-alpha1 group. CONCLUSION: The results suggest that a 6-mo course of T-alpha1 therapy is effective and safe in patients with chronic hepatitis B. T-alpha1 is able to reduce HBV replication in patients with chronic hepatitis B. Furthermore, T-alpha1 is better tolerated than IFN-alpha and can gradually induce more sustained ALT normalization and HBV DNA and HBeAg loss. However, a response rate of 48.3% is still less ideal. A more effective therapeutic approach warrants further study.

A randomized, controlled, clinical study of thymosin alpha-1 versus interferon-alpha in [corrected] patients with chronic hepatitis B lacking HBeAg in China [corrected].

BACKGROUND: This study was designed to compare the efficacy and safety of thymosin-alphal (T-alpha1) with that of interferon-alpha (IFN-alpha) in patients with chronic hepatitis B who were positive for hepatitis B virus (HBV) DNA and hepatitis B envelope antibody (anti-HBe). METHODS: Fifty-six patients were randomly divided into groups A and B. Both groups were comparable (p > 0.05) at baseline regarding age, sex, and alanine aminotransferase (ALT) levels. Group A patients received T-alpha1 1.6 mg subcutaneously twice weekly, while group B patients received IFN-alpha 5 million IU daily for 15 days, then thrice weekly for 6 months. Results from the 2 groups were compared with data from a group of 30 patients never treated with IFN-alpha and who were followed-up for 12 months (historical control [HC] group); the 3 groups were comparable (p > 0.05). RESULTS: After treatment, a complete response (ALT normalization and HBV DNA loss) occurred in 8 of 26 patients in group A (30.8%) and 14 of 30 in group B (46.7%; chi2 = 1.476, p = 0.224). After a follow-up period of 6 months, a complete response was observed in 11 of 26 patients in group A (42.3%) and 7 of 30 in group B (23.3%; chi2 = 2.299, p = 0.129). The rate of complete response was significantly greater in the IFN-alpha than HC group at the end of therapy (46.7% vs 3.3%; chi2 = 15.022, p = 0.0001), and in the T-alphal than HC group at the end of follow-up (42.3% vs 3.3%; chi2 = 12.566, p = 0.0001). Ten of the 12 T-alphal responders (i.e. partial responders; 83.3%) experienced sustained, non-detectable HBV DNA after 6 months' treatment; 6 of the 14 T-alphal non-responders (42.9%) showed a delayed response of non-detectable HBV DNA during the follow-up period. Corresponding values for group B patients were 50% (9/18) and 0% (0/12). The rate of delayed response was significantly higher in group A than the other 2 groups (chi2 = 6.686, p = 0.010; chi2 = 4.964, p = 0.038), whereas the rate of flare was higher in group B than in the other 2 groups (chi2 = 3.445, p = 0.063; chi2 = 7.668, p = 0.006), during the follow-up period. Unlike IFN-alpha, T-alphal was well tolerated, i.e. no adverse effects were noted in group A. CONCLUSION: These results suggest that a 6-month course of T-alpha1 therapy is effective and safe in patients with anti-HBe-positive chronic hepatitis B; T-alpha1 can reduce HBV replication in such patients. Compared with IFN-alpha, T-alpha1 is better tolerated and seems to induce a gradual and more sustained normalization of ALT and loss of HBV DNA. Combination therapy with T-alpha1 and IFN-alpha or nucleoside analogs for hepatitis B warrants further study.

Chiral separation of sertraline with microemulsion electrokinetic chromatography on a polymer/ß-cyclodextrin assembling molecular film modified capillary.

A capillary modified by assembling a molecular film was presented for the chiral separation of sertraline by microemulsion electrokinetic chromatography. The assembling molecular film was constructed with poly(diallyldimethylammonium-chloride) and ß-cyclodextrin via inclusion complexation. The separation efficiency of cis-trans isomers and enantiomers of sertraline was improved with a running microemulsion that contained the acetonitrile, sodium dodecyl sulfate, n-butanol and n-hexane buffered with sodium tetraborate. The baseline separation of four sertraline cis-trans isomers and enantiomers was achieved under the optimum conditions. The detection limit for isomers and enantiomers of sertraline (1S,4S, 1R,4R, 1S,4R, 1R,4S) was 0.15, 0.15, 0.30, 0.30 mg/L, respectively. The mechanism of chiral separation was studied and it could be applied for the determination of commercial Zoloft tablet samples satisfactorily.

[Determination of hydroxyl radical in CuSO4-vitamin C reaction system and scavenging activities of Chrysanthemum using capillary electrophoresis with electrochemical detection].

High performance capillary electrophoresis (CE) with electrochemical detection (ECD) was employed to determine the amount of hydroxyl radical in CuSO4-vitamin C reaction system (pH 7.4). The effects of some important factors, such as the acidity of the running buffer, separation voltage, injection time and the potential applied to the working electrode were investigated to choose the CE-ECD optimum conditions. The reaction system to produce hydroxyl radical was also optimized such as the effects of reactant concentration and reaction time on the concentration of 3,4-dihydroxy-benzoic acid. Operated in a wall-jet configuration, a 300 microm diameter carbon-disc electrode was used as the working electrode. Excellent linearity was obtained in the concentration ranging from 1.5 x 10(-4) mol/L to 6.0 x 10(-6) mol/L for the reaction product. The detection limit was 1.5 x 10(-6) mol/L (S/N = 3). This method was successfully applied to determine scavenging activities of Chrysanthemum for hydroxyl radical.