Extent of Enzyme Inhibition by Phenolics Derived from Pretreated Biomass Is Significantly Influenced by the Size and Carbonyl Group Content of the Phenolics

In the current biorefinery concept, hydrothermal-based pretreatments such as steam pretreatment are often used to first open up the plant cell wall structure and increase the accessibility of the cellulose component to cellulase enzymes. However, this pretreatment process also generates water-soluble phenolics that are strongly inhibitory to the cellulase enzymes, therefore limiting the efficiency of the enzymatic hydrolysis of the pretreated biomass. Although some earlier work assessed the influence of phenolics on cellulose hydrolysis, the characteristics of the phenolics that most influenced inhibition have not yet been elucidated. As biomass-derived phenolics are heterogeneous monomer/oligomeric/polymeric aromatic compounds that have diverse functional groups and varied molecular size, the current work investigated the influence of the major structural properties of the pretreatment-derived phenolics, such as their molecular weight and the nature of their hydroxyl and carbonyl groups, on enzyme inhibition. It was apparent that phenolics derived from steam-pretreated softwood were more inhibitory than the phenolics derived from steam-pretreated hardwoods with phenolics with a smaller molecular size and greater carbonyl content being more inhibitory to enzyme-catalyzed cellulose hydrolysis

SUMOylation of p53b induced apoptosis in granulosa cells.

<p>(A) Representative flow cytometric analysis of apoptotic cells stained with Annexin V-FITC and PI after transfection with 2 µg wild type p53b, mutant p53b (K375R) plasmid, control plasmid or non-transfection control group for 24 h. In each panel, the lower right quadrant contains apoptotic cells (positive for Annexin V and negative for PI). (B) The apoptosis rate of granulosa cells. The value expressed by each bar represents the mean ± SD (n = 3). Different superscripts denote statistical difference at a <i>P</i><0.05. (C) Expression level of <i>Bax</i> mRNA. 24 h after transfection with 2 µg wild type p53b, mutant p53b (K375R), control plasmid or non-transfection control group, expression level of <i>Bax</i> mRNA was detected by quantitative real-time PCR. Fold changes were calculated from <i>β-actin</i> normalized Ct values. The value expressed by each bar represents the mean ± SD (n = 3). Different superscripts denote statistical difference at a <i>P</i><0.05.</p

SUMOylation increased the expression level of mouse p53 protein.

<p>Pre-GCs were seeded in 6-well culture plates and transfected with 2 µg of HA-p53a, HA-p53b, HA-sumo-1, HA-ubc9, or empty HA expression plasmids. 20 µg total extracts were prepared and resolved by SDS–PAGE and analyzed by Western blot using anti-HA (the top group) or anti-p53 (the middle group) specific antibody. Positions of molecular weight markers, free HA-p53 or putative p53/HA–SUMO-1 and p53/HA-UBC9 conjugates are indicated. β-actin is a loading control.</p

Data_Sheet_1_Strain-Specific Anti-inflammatory Properties of Two Akkermansia muciniphila Strains on Chronic Colitis in Mice.pdf

Akkermansia muciniphila is potential probiotic in that its type strain ATCC BAA-835 has beneficial effects upon obesity and diabetes. However, whether A. muciniphila can improve inflammatory bowel diseases (IBD), which is a form of chronic intestinal dysbiosis, is unknown. Hence, we used an isolated murine A. muciniphila strain (designated 139) and A. muciniphila type strain ATCC, to investigate their anti-inflammatory properties in cell models and in Dextran Sulfate Sodium (DSS)-induced chronic colitis of mice. In vitro, the two A. muciniphila strains exerted similar anti-inflammatory properties as they both reduced IL-8 production by TNF-α-stimulated HT-29 cells. However, neither of the strains showed capacity to increase the differentiation of regulatory T (Treg)-cells from CD4+ T cell populations significantly. In vivo, both A. muciniphila strains exerted anti-inflammatory effects on chronic colitis as they improved clinical parameters including spleen weight, colon inflammation index, and colon histological score. They also down-regulated the expression of the pro-inflammatory cytokines including TNF-α and IFN-γ in the colon of mice. However, the anti-inflammatory effects of strain ATCC were stronger than strain 139 in that ATCC significantly reduced spleen weight, colon inflammation index, and fecal lipocalin-2 content in mice with chronic colitis, while strain 139 was not. Dysbiosis of the gut microbiota was observed in mice with chronic colitis. Both A. muciniphila strains facilitated the normalization of the gut microbiota. The specific capacity of strain ATCC to modulate the differentiation of Tregs as well as increase production of short chain fatty acids, demonstrated strain-specific characteristics for these two A. muciniphila strains. This study suggests the potential beneficial effect of A. muciniphila on IBD and the importance of the future study of the function of A. muciniphila at the strain-level.</p

Growth of SiC Nanowires from NiSi Solution

We present a simple melt solution strategy for the growth of high-yield SiC nanowires out of NiSi solution. The growth temperature and base vacuum before filling argon during the reaction are found to have a significant effect on the morphology of the product growth. Taking into consideration the action of Ni in the NiSi melt and the possible participation of a tiny amount of oxygen, the formation of SiC nanowires is discussed by a combination of the solid−liquid−solid reaction for nucleation and the vapor−liquid−solid process for nanowire growth. The nanowires were also investigated with Raman spectroscopy. Such a simple and economical method may be extended to synthesize other one-dimensional nanostructures

Additional file 1 of Understanding the structural characteristics of water-soluble phenolic compounds from four pretreatments of corn stover and their inhibitory effects on enzymatic hydrolysis and fermentation

Additional file 1. Additional figures and tables

Engineered Biosynthesis and Anticancer Studies of Ring-Expanded Antimycin-Type Depsipeptides

Respirantins are 18-membered antimycin-type depsipeptides produced by Streptomyces sp. and Kitasatospora sp. These compounds have shown extraordinary anticancer activities against a panel of cancer cell lines with nanomolar levels of IC50 values. However, further investigation has been impeded by the low titers of the natural producers and the challenging chemical synthesis due to their structural complexity. The biosynthetic gene cluster (BGC) of respirantin was previously proposed based on a bioinformatic comparison of the four members of antimycin-type depsipeptides. In this study, we report the first successful reconstitution of respirantin in Streptomyces albus using a synthetic BGC. This heterologous system serves as an accessible platform for the production and diversification of respirantins. Through polyketide synthase pathway engineering, biocatalysis, and chemical derivatization, we generated nine respirantin compounds, including six new derivatives. Cytotoxicity screening against human MCF-7 and Hela cancer cell lines revealed a unique biphasic dose–response profile of respirantin. Furthermore, a structure–activity relationship study has elucidated the essential functional groups that contribute to its remarkable cytotoxicity. This work paves the way for respirantin-based anticancer drug discovery and development

Identification of SUMOylation of p53b in vivo at Lys 375.

<p>(A) Immunoprecipitation analysis of SUMOylation of p53 in vivo. Pre-GCs were transfected with pCMV-Flag-sumo-1 plasmid or pCMV-Flag plasmid. Flag-tagged protein were pulled down by anti-Flag affinity beads and then analyzed by Western blot using anti-p53 antibody. A visible band of p53 was detected in the sample of pCMV-Flag-sumo-1 transfected granulosa cells, but not in the control sample. (B) SUMOylation consensus site aligned in sequences of p53 from human and mouse. The SUMOylation consensus site is ψKXE with a hydrophobic residue, such as Phenylalanine (F), Isoleucine (I), or Leucine (L). Sequences of human p53 and mouse p53b were aligned. Lys386 in human p53 is SUMO-1 modified and the mouse p53b has a highly homologous sequence to this SUMOylation site. (C) Co-immunoprecipitation of SUMO-1 with p53a or p53b. Pre-GCs were co-transfected with Flag-tagged sumo-1 plasmid and HA-tagged p53a or HA-tagged p53b plasmid. Flag-tagged proteins were pulled down by anti-Flag affinity beads and then analyzed by Western blot using anti-HA antibody. A band of p53 (p53b) was detected in the sample of Flag-sumo-1 plasmid and HA-p53b plasmid co-transfected granulosa cells, but not in the HA-p53a plasmid and Flag-sumo-1 plasmid co-transfection group or control sample. (D) p53b is SUMOylated at lys375. Pre-GCs were co-transfected with 2 µg of wild type HA-p53b or mutant p53b (K375R) plasmid and 2 µg of Flag-sumo-1 plasmid. 20 µg total extracts were prepared and resolved by SDS–PAGE and analyzed by Western blot using the anti-HA-specific antibody. Positions of molecular weight markers, free p53 or p53-SUMO-1 conjugates are indicated. β-actin is a loading control. After transfection, two bands could be detected in the group with co-transfection of wild type p53b and sumo-1, the lower molecular weight below was considered as free p53b and the higher molecular weight above was p53b-SUMO-1 as the SUMOylated p53b, but only one band (mutant p53b) could be observed in the group with co-transfection of mutant p53b and sumo-1 plasmids, while the p53b (K375R)-SUMO-1- band was not observed.</p