Insekten als Nahrungsmittel der Zukunft

Insects as a sustainable food of the future In Germany insects are still relatively unknown as foodstuff. However, in many countries of the world insects have been valued as foodstuff for a long time. This article examines the sustainability potential of entomophagy. Based on legal and psychological barriers it tries to explain why insects are not on the menu in Germany. Research in the fields of nutritional psychology and biodidactics is essential for the successful introduction of insects as foodstuff in Germany.     

Cholest-4-en-3-one attenuates TGF-β responsiveness by inducing TGF-β receptors degradation in Mv1Lu cells and colorectal adenocarcinoma cells

Purpose: The transforming growth factor-beta (TGF-β) pathway is an important in the initiation and progression of cancer. Due to a strong association between an elevated colorectal cancer risk and increase fecal excretion of cholest-4-en-3-one, we aim to determine the effects of cholest-4-en-3-one on TGF-β signaling in the mink lung epithelial cells (Mv1Lu) and colorectal cancer cells (HT29) in vitro.

Methods: The inhibitory effects of cholest-4-en-3-one on TGF-β-induced Smad signaling, cell growth inhibition, and the subcellular localization of TGF-β receptors were investigated in epithelial cells using a Western blot analysis, luciferase reporter assays, DNA synthesis assay, confocal microscopy, and subcellular fractionation.

Results: Cholest-4-en-3-one attenuated TGF-β signaling in Mv1Lu cells and HT29 cells, as judged by a TGF-β-specific reporter gene assay of plasminogen activator inhibitor-1 (PAI-1), Smad2/3 phosphorylation and nuclear translocation. We also discovered that cholest-4-en-3-one suppresses TGF-β responsiveness by increasing lipid raft and/or caveolae accumulation of TGF-β receptors and facilitating rapid degradation of TGF-β and thus suppressing TGF-β-induced signaling.

Conclusions: Our results suggest that cholest-4-en-3-one inhibits TGF-β signaling may be due, in part to the translocation of TGF-β receptor from non-lipid raft to lipid raft microdomain in plasma membranes. Our findings also implicate that cholest-4-en-3-one may be further explored for its potential role in colorectal cancer correlate to TGF-β deficiency.     

A peptide inhibitor of MurA UDP-N-acetylglucosamine enolpyruvyl transferase: the first committed step in peptidoglycan biosynthesis

The MurA enzyme from Pseudomonas aeruginosa was purified to homogeneity and found to be biologically active as a UDP-N-acetylglucosamine (UNAG) enolpyruvyl transferase in a coupled enzyme assay where ATPase activity was measured by the release of inorganic phosphate. A microtiter plate assay coupled to competitive biopanning using the UDP-N-acetylglucosamine was used to screen 10⁹ C-7-C and 12-mers peptides from phage display libraries. From 60 phage-encoded peptides identified after the fourth round of biopanning, deduced amino acid sequences were aligned and two peptides were synthesized and tested for inhibition of the MurA-catalyzed reaction. The PEP 1354 peptide inhibited the ATPase activity of MurA with an IC₅₀ value of 200 μM and was found to be a competitive inhibitor of UNAG. The pre-incubation of MurA with inhibitor indicated a time-independent inhibition. This time-dependent inhibition is the first report of peptide inhibitors of MurA, which represent the scaffold for the synthesis of inhibitory peptidomimetic molecules.     

Anthocyanin Accumulation Mediated by Blue Light and Cytokinin in Arabidopsis Seedlings

It has been reported that pigmentation In plants Is stimulated by light and cytoklnln （CTK）; however, the signaling pathways and the relationship between light and CTK Involved In the regulation of anthocyanln accumulation remain to be elucidated. We Investigated （i） the role of blue light （BL） and CTK In anthocyanln accumulation ; and （ii） the relationship between BL and CTK In wild type （WT） and by4 mutants of Arabidopsis thaiiana. Two-d-old seedlings grown on medium with or without klnetln （KT） or zeatln （ZT） In darkness were Irradiated using BL at different fluence rates for 3 d before the anthocyanln content was determined using a spectrophotometrlc method. Anthocyanln accumulation was strongly Induced by BL In WT seedlings but not In hy4 seedlings, which demonstrated that CRY1 Is the main photoreceptor for BL. Both KT and ZT enhanced the response of the WT seedlings to BL In a dose-dependent manner, whereas they were not sufficient to promote anthocyanln eccumulatlon In darkness. In addition, data from experiments using the hy4 mutant showed that the CTK effect of BL was also CRYl-dependent. The results from experiments with three different treatment programs showed that the relationship between BL and KT In anthocyanln accumulation of Arabidopsis seedlings seems neither muItlpllcatlve nor additive coactlon, but rather Interaction. BL Is necessary for anthocyanln accumulation, and KT might be Involved In the BL signaling pathway.     

Regulation of Eukaryotic Initiation Factor 4E and Its Isoform： Implications for Antiviral Strategy in Plants

In recent years, biotechnology has permitted regulation of the expression of endogenous plant genes to improve agronomlcally important traits. Genetic modification of crops has benefited from emerging knowledge of new genes, especially genes that exhibit novel functions, one of which is eukaryotlc initiation factor 4E （eIF4E）. eIF4E Is one of the most important translation initiation factors Involved in eukaryotic initiation. Recent research has demonstrated that virus resistance mediated by eIF4E and Its isoform elf （Iso）4E occurs in several plant-virus interactions, thus indicating a potential new role for eIF4E/elF（Iso）4E In resistance strategies against plant viruses. In this review, we briefly describe eIF4E activity In plant translation, its potential role, and functions of the eIF4E subfamily In plant-virus interactions. Other initiation factors such as elF4G could also play a role In plant resistance against viruses. Finally, the potential for developing eIF4E-mediated resistance to plant viruses in the future Is discussed. Future research should focus on elucidation of the resistance mechanism and spectrum mediated by eIF4E. Knowledge of a particu- lar plant-virus interaction will help to deepen our understanding of eIF4E and other eukaryotic Initiation factors, and their involvement in virus disease control.     

水稻可溶性糖蛋白的纯化与鉴定研究

从水稻鲜叶中提取总蛋白,对总蛋白中的蛋白质含量进行了测定;通过硫酸铵沉淀将总蛋白提取液进行分级,从而达到了总蛋白细分和放量的目的。四级份的分级蛋白分别通过ConA-Sepharose 4B 亲和层析进行糖蛋白纯化,按吸收峰收集的各级糖蛋白混合物进行冷冻干燥,得到干粉;结合PAS法染色和考马斯亮蓝R-250染色对四级份的糖蛋白样品鉴定,在其中3个级份中均检测出糖蛋白;由于感度的差异,按考马斯亮蓝R-250染色可检测出近30种糖蛋白(包括部分糖肽),按PAS法染色可检测到7种糖蛋白;对3种含量较高的糖蛋白进行了胶上纯化,3种糖蛋白的PAS法染色均证实了3种样品为单一的糖蛋白或者糖肽,分别命名为RG1、RG2和RG3。     

利用噬菌体随机肽库筛选抗柯萨奇病毒B3多肽的研究

本实验将柯萨奇病毒B3型(CVB3)大量扩增,应用蔗糖密度梯度离心法纯化病毒。利用噬菌体随机9肽库进行筛选,3轮淘洗后,测定噬菌体克隆抗病毒复制能力。提取阳性克隆DNA并进行测序,推导外源多肽的氨基酸序列。结果表明:3个具有明显抗病毒复制能力的噬菌体阳性克隆被筛选出来,使TCID50由10-7.5SFU/mL分别降至10-5.25、10-6、10-5.5SFU/mL,由此证明可以应用噬菌体肽库来筛选具有抗病毒作用的多肽,本研究为抗病毒多肽制剂的研究奠定了基础。     

Arabidopsis CYP90B1 catalyses the early C-22 hydroxylation of C27, C28 and C29 sterols

Arabidopsis dwf4 is a brassinosteroid (BR)-deficient mutant, and the DWF4 gene encodes a cytochrome P450, CYP90B1. We report the catalytic activity and substrate specificity of CYP90B1. Recombinant CYP90B1 was produced in Escherichia coli, and CYP90B1 activity was measured in an in vitro assay reconstituted with NADPH-cytochrome P450 reductase. CYP90B1 converted campestanol (CN) to 6-deoxocathasterone, confirming that CYP90B1 is a steroid C-22 hydroxylase. The substrate specificity of CYP90B1 indicated that sterols with a double bond at positions C-5 and C-6 are preferred substrates compared with stanols, which have no double bond at the position. In particular, the catalytic efficiency (k(cat)/K(m)) of CYP90B1 for campesterol (CR) was 325 times greater than that for CN. As CR is more abundant than CN in planta, the results suggest that C-22 hydroxylation of CR before C-5alpha reduction is the main route of BR biosynthetic pathway, which contrasts with the generally accepted route via CN. In addition, CYP90B1 showed C-22 hydroxylation activity toward various C(27-29) sterols. Cholesterol (C27 sterol) is the best substrate, followed by CR (C28 sterol), whereas sitosterol (C29 sterol) is a poor substrate, suggesting that the substrate preference of CYP90B1 may explain the discrepancy between the in planta abundance of C27/C28/C29 sterols and C27/C28/C29 BRs.     

Kdo2-Lipid A of Escherichia coli, a defined endotoxin that activates macrophages via TLR-4

The LIPID MAPS Consortium (www.lipidmaps.org) is developing comprehensive procedures for identifying all lipids of the macrophage, following activation by endotoxin. The goal is to quantify temporal and spatial changes in lipids that occur with cellular metabolism and to develop bioinformatic approaches that establish dynamic lipid networks. To achieve these aims, an endotoxin of the highest possible analytical specification is crucial. We now report a large-scale preparation of 3-deoxy-D-manno-octulosonic acid (Kdo)(2)-Lipid A, a nearly homogeneous Re lipopolysaccharide (LPS) sub-structure with endotoxin activity equal to LPS. Kdo(2)-Lipid A was extracted from 2 kg cell paste of a heptose-deficient Escherichia coli mutant. It was purified by chromatography on silica, DEAE-cellulose, and C18 reverse-phase resin. Structure and purity were evaluated by electrospray ionization/mass spectrometry, liquid chromatography/mass spectrometry and (1)H-NMR. Its bioactivity was compared with LPS in RAW 264.7 cells and bone marrow macrophages from wild-type and toll-like receptor 4 (TLR-4)-deficient mice. Cytokine and eicosanoid production, in conjunction with gene expression profiling, were employed as readouts. Kdo(2)-Lipid A is comparable to LPS by these criteria. Its activity is reduced by >10(3) in cells from TLR-4-deficient mice. The purity of Kdo(2)-Lipid A should facilitate structural analysis of complexes with receptors like TLR-4/MD2.     

A proteomic approach for dissecting H-Ras signaling networks in NIH/3T3 mouse embryonic fibroblast cells

To elucidate an understanding into H-Ras protein network, we have established various oncogene H-Ras-expressing NIH/3T3 mouse embryonic fibroblast cell clones, which are expressing G12V H-Ras, G12R H-Ras, and G12V/T35S H-Ras proteins under the tight control of expression by an antibiotic doxycycline. Here we provide a catalog of proteome profiles in total cell lysate derived from the oncogenic and partial loss of function H-Ras-expressing NIH/3T3 cells. In this biological context, we compared total proteome changes by the combined methods of 2-DE, quantitative image analysis and MALDI-TOF-MS analysis both commonly in oncogenic and partial loss of function H-Ras expression system. Thus, we tried to dissect H-Ras signaling pathway, especially a downstream effector molecule, Raf in NIH/3T3 cells using proteomics tools. In this study, we centralized upon the proteome profile changes as common targets for oncogenic H-Ras and a partial loss of function H-Ras in the H-Ras-expressing cells. Thirteen protein spots were selected as what the staining intensities on the gels for 2-DE images from both kinds of cells were consistently changed in their protein expression level. Differentially regulated expression was further confirmed for some subsets of candidates by semiquantitative RT-PCR and Western blot analysis using specific antibodies. Taken together, our results obtained and present here show that the comparative analysis of proteome from oncogenic and partial loss of function H-Ras-expressing cells has yielded interpretable data to elucidate the protein network directly and/or indirectly.