Search results for "second"
showing 10 items of 3671 documents
Plasma modified PLA electrospun membranes for actinorhodin production intensification in Streptomyces coelicolor immobilized-cell cultivations
2017
Most of industrially relevant bioproducts are produced by submerged cultivations of actinomycetes. The immobilization of these Gram-positive filamentous bacteria on suitable porous supports may prevent mycelial cell-cell aggregation and pellet formation which usually negatively affect actinomycete submerged cultivations, thus, resulting in an improved biosynthetic capability. In this work, electrospun polylactic acid (PLA) membranes, subjected or not to O2-plasma treatment (PLA-plasma), were used as support for immobilized-cell submerged cultivations of Streptomyces coelicolor M145. This strain produces different bioactive compounds, including the blue-pigmented actinorhodin (ACT) and red-p…
Parsimonious Scenario for the Emergence of Viroid-Like Replicons De Novo
2019
This article belongs to the Special Issue Viroid-2018: International Conference on Viroids and Viroid-Like RNAs. Viroids are small, non-coding, circular RNA molecules that infect plants. Different hypotheses for their evolutionary origin have been put forward, such as an early emergence in a precellular RNA World or several de novo independent evolutionary origins in plants. Here, we discuss the plausibility of de novo emergence of viroid-like replicons by giving theoretical support to the likelihood of different steps along a parsimonious evolutionary pathway. While Avsunviroidae-like structures are relatively easy to obtain through evolution of a population of random RNA sequences of fixe…
Insights into the Structure of the Vip3Aa Insecticidal Protein by Protease Digestion Analysis
2017
Vip3 proteins are secretable proteins from Bacillus thuringiensis whose mode of action is still poorly understood. In this study, the activation process for Vip3 proteins was closely examined in order to better understand the Vip3Aa protein stability and to shed light on its structure. The Vip3Aa protoxin (of 89 kDa) was treated with trypsin at concentrations from 1:100 to 120:100 (trypsin:Vip3A, w:w). If the action of trypsin was not properly neutralized, the results of SDS-PAGE analysis (as well as those with Agrotis ipsilon midgut juice) equivocally indicated that the protoxin could be completely processed. However, when the proteolytic reaction was efficiently stopped, it was revealed t…
The C-terminal region of human plasma fetuin-B is dispensable for the raised-elephant-trunk mechanism of inhibition of astacin metallopeptidases
2019
© The Author(s) 2019.
Lunasin is a redox sensitive intrinsically disordered peptide with two transiently populated α-helical regions.
2016
Lunasin is a 43 amino acid peptide with anti-cancer, antioxidant, anti-inflammatory and cholesterol-lowering properties. Although the mechanism of action of lunasin has been characterized to some extent, its exact three-dimensional structure as well as the function of the N-terminal sequence remains unknown. We established a novel method for the production of recombinant lunasin that allows efficient isotope labeling for NMR studies. Initial studies showed that lunasin can exist in a reduced or oxidized state with an intramolecular disulfide bond depending on solution conditions. The structure of both forms of the peptide at pH 3.5 and 6.5 was characterized by CD spectroscopy and multidimen…
In vivo selection of heterotypically interacting transmembrane helices: Complementary helix surfaces, rather than conserved interaction motifs, drive…
2017
Single pass transmembrane proteins make up almost half of the whole transmembrane proteome. Contacts between such bitopic transmembrane proteins are common, and oligomerization of their single transmembrane helix is involved in triggering and regulation of signal transduction across cell membranes. In several recent analyses the distribution of amino acids at helix-helix contact sides has been analyzed, and e.g. a preference of amino acids with small side chains has been identified. Here we select amino acids, amino acid pairings and amino acid motifs, which mediate strong interactions of single-span transmembrane α-helices. Our analysis illustrates an architecture of TM helix dimers that i…
The Novel Oral Anticoagulants for Acute Venous Thromboembolism: Is Warfarin Dead?
2017
The direct oral anticoagulants (DOACs) have been compared with parenteral anticoagulants and vitamin K antagonists (VKAs) for the treatment of venous thromboembolism (VTE) in several robust studies. DOACs have shown similar efficacy in preventing recurrent VTE and significant reductions in critical site (intracranial) bleeding, fatal bleeding, major and nonmajor bleeding. Warfarin and other VKAs are not dead as treatment modalities for VTE. A better way to describe the current situation is to use a boxing expression, “down but not out.” VKAs and parenteral anticoagulants still have a role to play in the management of VTE in several clinical settings. In indications where DOACs can be used, …
Root Canal Morphology of 116 Maxillary Second Premolars by Micro–Computed Tomography in a Mixed Swiss-German Population with Systematic Review
2020
Abstract Introduction The aim of this investigation was to examine the root canal system morphology of maxillary second premolars (Mx2Ps) of a Swiss-German population by means of micro–computed tomography and provide systematic review of the root canal configuration (RCC) literature of Mx2Ps. Methods The RCC, main foramina as well as accessory canals and foramina frequency of 116 Mx2Ps, were investigated by means of micro–computed tomography and 3-dimensional software imaging. The RCC from the coronal to apical thirds of the root as well as the main foramina number were described by using a four-digit system code. The literature review follows the PRISMA guideline analyzing randomized contr…
Resistance against Echinostoma caproni (Trematoda) secondary infections in mice is not dependent on the ileal protein production
2016
Echinostoma caproni (Trematoda: Echinostomatidae) is an intestinal trematode, which has been widely employed to investigate the factors determining the rejection of intestinal helminths. Protein production patterns of intestinal epithelial cells are related to the infection-induced changes that determine the course of E. caproni infections. Herein, we compare the protein production profiles in the ileum of four experimental groups of mice: control; infected; dewormed and reinfected. Worm burdens were significantly lower in secondary infections, confirming the generation of partial resistance to homologous secondary infections in mice. However, quantitative comparison by 2D-DIGE showed that …
Secondary Progression in Multiple Sclerosis: Neuronal Exhaustion or Distinct Pathology?
2016
Prevention of progression in neurological diseases, particularly in multiple sclerosis (MS) but also in neurodegenerative diseases, remains a significant challenge. MS patients switch from a relapsing-remitting to a progressive disease course, but it is not understood why and how this conversion occurs and why some patients never experience disease progression. Do aging and accumulation of neuronal damage induce progression, or do cognitive symptoms and accelerated grey matter (GM) atrophy point to distinct processes affecting networks? This review weighs accepted dogma against real data on the secondary progressive phase of the disease, highlighting current challenges in this important fie…