Synthesis of n-butyl acetate via reactive distillation column using Candida Antarctica lipase as catalyst

Bioprocess and Biosystems Engineering - The reactive distillation process for the synthesis of n-butyl acetate via transesterification of ethyl acetate with n-butyl alcohol catalyzed by immobilized...     

MMS2plot: An R Package for Visualizing Multiple MS/MS Spectra for Groups of Modified and Non‐Modified Peptides

A large number of post‐translational modifications (PTMs) in proteins are buried in the unassigned mass spectrometric (MS) spectra in shot‐gun proteomics datasets. Because the modified peptide fragments are low in abundance relative to the corresponding non‐modified versions, it is critical to develop tools that allow facile evaluation of assignment of PTMs based on the MS/MS spectra. Such tools will preferably have the ability to allow comparison of fragment ion spectra and retention time between the modified and unmodified peptide pairs or group. Herein, MMS2plot, an R package for visualizing peptide‐spectrum matches (PSMs) for multiple peptides, is described. MMS2plot features a batch mode and generates the output images in vector graphics file format that facilitate evaluation and publication of the PSM assignment. MMS2plot is expected to play an important role in PTM discovery from large‐scale proteomics datasets generated by liquid chromatography‐MS/MS. The MMS2plot package is freely available at https://github.com/lileir/MMS2plot under the GPL‐3 license.     

Depth-dependent indicators of algal turf herbivory throughout the Main Hawaiian Islands

Herbivorous fish are key to maintaining a balance between coral and algae on reefs, where reefs with greater herbivore biomass often show lower algal cover. For reefs worldwide, algal turf cover is expanding and is increasingly used as an indicator of disturbance. Water depth affects reef fish composition; thus, it may be expected that herbivory could also differ by depth. We examined relationships between algal turf cover and biomass (g m⁻²), density (# m⁻²) and size (cm) of herbivore groups (grazers, browsers and scrapers) across shallow (< 6 m), mid (6–18 m) and deep (18–30 m) coral reefs in the Main Hawaiian Islands. We find that across all depth classes, algal turf cover decreased with increasing grazer and scraper density, with steeper relationships observed at mid and deep reefs than in shallow reefs. In contrast, algal turf cover slightly increased with increasing grazer and browser biomass at deep reefs. Considering fish size, algal turf cover increased with larger grazer and scrapers at mid and deep reefs. The results indicate that herbivorous fish density, rather than biomass, is a better indicator of reductions in algal turf cover and resulting coral-algal balance on Hawaiian reefs, where smaller fish exert greater top-down control on cover than larger fish. Despite significant differences in herbivorous fish compositions, length-frequency distributions and fishing intensities across depth, algal turf cover remains similar across depths. Increases in fishing would have a disproportionately negative impact in deep than shallow reefs due to a lower overall fish density, where grazing functions in deep reefs are maintained by significantly fewer and smaller grazers and browsers, and larger scrapers, than in shallow reefs. Developing an understanding of patterns of algal turf herbivory by depth is important to understanding the spatial scale at which herbivory and regime shifts operate.

     

Peptides YYGGEGSSSEQG and SESEM Inhibit TNF-α-Induced Smooth Muscle Cells Proliferation and Migration Through Their Bindings to TNF-α Receptor

International Journal of Peptide Research and Therapeutics - The peptides YYGGEGSSSEQG and SESEM derived from rice α-globulin have been reported to possess anti-atherosclerotic activity, but...     

Impacts of remotely sensed environmental drivers on coral outplant survival

Globally, coral reefs are degrading due to a variety of stressors including climate change and pollution. Active restoration is an important effort for sustaining coral reefs where, typically, coral fragments are outplanted onto degraded reefs. Coral outplants, however, can experience mortality in response to a range of stressors. We pair results of outplant monitoring observations with satellite‐based measurements of multiple oceanographic variables to estimate the relative importance of each driver to coral outplant survival. We find that when considering mean environmental conditions experienced by outplants during the monitoring period, particulate organic carbon (POC) levels are most important in determining outplant survival, with certain levels of POC beneficial for outplants. Sea surface temperature anomalies (SSTA) are also important determinants of outplant survival, where survival is greatest in regions with minimal or slightly negative anomalies. Survival also increases with increasing distance to land, likely due to a reduction in negative ridge‐to‐reef effects on coral outplants. When considering the range (min–max) of environmental conditions experienced during the monitoring period, large fluctuations in photosynthetically active radiation (PAR) and POC are most important in determining outplant survival. Increasing outplant depth can help to counter the negative impacts of large fluctuations in environmental variables. We find that a variety of remotely sensed oceanographic variables have significant impacts on survival and should be considered in coral restoration planning to help evaluate potential restoration sites and ultimately maximize coral outplant survival.     

Dahuang Zhechong pill attenuates CCl4-induced rat liver fibrosis via the PI3K-Akt signaling pathway

It is well characterized that activated hepatic stellate cells (HSCs) exert critical functions in accelerating the progression of liver fibrosis. Previous studies have indicated that Dahuang Zhechong pill (DHZCP), a traditional Chinese herbal medicine, is capable of inactivating HSCs and thus attenuate the formation of liver fibrosis in rats. However, pharmacological mechanisms of DHZCP in alleviating liver fibrosis remain unclear. This study aims to investigate the antifibrotic role of DHZCP through inhibiting the phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt) pathway. DHZCP was found to significantly suppresses extracellular matrix formation and immune cell infiltration, thus alleviating liver fibrosis symptoms in the in vivo model. Moreover, DHZCP reduced serum levels of transforming growth factor β1 and tumor necrosis factor-α in rats with liver fibrosis. DHZCP treatment remarkably downregulated protein levels of PI3K and phosphorylated Akt, as well as fibrosis markers. In vitro experiments further demonstrated that DHZCP markedly suppressed HSCs proliferation by downregulating PI3K/Akt, which exerted a synergistic effect with the PI3K inhibitor LY294002. To sum up, our results confirmed that DHZCP exerted an antifibrotic effect in the animal model through inactivating the PI3K/Akt pathway, thus protecting rats from liver injury.     

A Novel Domain of Amino-Nogo-A Protects HT22 Cells Exposed to Oxygen Glucose Deprivation by Inhibiting NADPH Oxidase Activity

This study aimed to investigate the protective effect of the M9 region (residues 290–562) of amino-Nogo-A fused to the human immunodeficiency virus trans-activator TAT in an in vitro model of ischemia–reperfusion induced by oxygen–glucose deprivation (OGD) in HT22 hippocampal neurons, and to investigate the role of NADPH oxidase in this protection. Transduction of TAT-M9 was analyzed by immunofluorescence staining and western blot. The biologic activity of TAT-M9 was assessed by its effects against OGD-induced HT22 cell damage, compared with a mutant M9 fusion protein or vehicle. Cellular viability and lactate dehydrogenase (LDH) release were assessed. Neuronal apoptosis was evaluated by flow cytometry. The Bax/Bcl-2 ratio was determined by western blotting. Reactive oxygen species (ROS) levels and NADPH oxidase activity were also measured in the presence or absence of an inhibitor or activator of NADPH oxidase. Our results confirmed the delivery of the protein into HT22 cells by immunofluorescence and western blot. Addition of 0.4 μmol/L TAT-M9 to the culture medium effectively improved neuronal cell viability and reduced LDH release induced by OGD. The fusion protein also protected HT22 cells from apoptosis, suppressed overexpression of Bax, and inhibited the reduction in Bcl-2 expression. Furthermore, TAT-M9, as well as apocynin, decreased NADPH oxidase activity and ROS content. The protective effects of the TAT-M9 were reversed by TBCA, an agonist of NADPH oxidase. In conclusion, TAT-M9 could be successfully transduced into HT22 cells, and protected HT22 cells against OGD damage by inhibiting NADPH oxidase-mediated oxidative stress. These findings suggest that the TAT-M9 protein may be an efficient therapeutic agent for neuroprotection.     

In Human Pseudouridine Synthase 1 (hPus1), a C-Terminal Helical Insert Blocks tRNA from Binding in the Same Orientation as in the Pus1 Bacterial Homologue TruA,Consistent with Their Different Target Selectivities

Human pseudouridine (Ψ) synthase Pus1 (hPus1) modifies specific uridine residues in several non-coding RNAs: tRNA, U2 spliceosomal RNA, and steroid receptor activator RNA. We report three structures of the catalytic core domain of hPus1 from two crystal forms, at 1.8 Å resolution. The structures are the first of a mammalian Ψ synthase from the set of five Ψ synthase families common to all kingdoms of life. hPus1 adopts a fold similar to bacterial Ψ synthases, with a central antiparallel β-sheet flanked by helices and loops. A flexible hinge at the base of the sheet allows the enzyme to open and close around an electropositive active-site cleft. In one crystal form, a molecule of Mes [2-(N-morpholino)ethane sulfonic acid] mimics the target uridine of an RNA substrate. A positively charged electrostatic surface extends from the active site towards the N-terminus of the catalytic domain, suggesting an extensive binding site specific for target RNAs. Two α-helices C-terminal to the core domain, but unique to hPus1, extend along the back and top of the central β-sheet and form the walls of the RNA binding surface. Docking of tRNA to hPus1 in a productive orientation requires only minor conformational changes to enzyme and tRNA. The docked tRNA is bound by the electropositive surface of the protein employing a completely different binding mode than that seen for the tRNA complex of the Escherichia coli homologue TruA.