Search results for "Lytic"

Cooperation between CRISPR-Cas types enables adaptation in an RNA-targeting system

2020

AbstractCRISPR-Cas immune systems adapt to new threats by acquiring spacers from invading nucleic acids such as phage genomes. However, some CRISPR-Cas loci lack genes necessary for spacer acquisition, despite apparent variation in spacer content between strains. It has been suggested that such loci may use acquisition machinery from co-occurring CRISPR-Cas systems. Here, using a lytic dsDNA phage, we observe spacer acquisition in the native host Flavobacterium columnare that carries an acquisition-deficient subtype VI-B locus and a complete subtype II-C locus. We characterize acquisition events in both loci and show that the RNA-targeting VI-B locus acquires spacers in trans using acquisit…

Comparison of CRISPR and marker based methods for the engineering of phage T7

2020

With the recent rise in interest in using lytic bacteriophages as therapeutic agents, there is an urgent requirement to understand their fundamental biology to enable the engineering of their genomes. Current methods of phage engineering rely on homologous recombination, followed by a system of selection to identify recombinant phages. For bacteriophage T7, the host genescmkortrxhave been used as a selection mechanism along with both type I and II CRISPR systems to select against wild-type phage and enrich for the desired mutant. Here we systematically compare all three systems; we show that the use of marker-based selection is the most efficient method and we use this to generate multiple …

2020

The term “amyloid” refers to proteinaceous deposits of peptides that might be generated from larger precursor proteins e.g., by proteolysis. Common to these peptides is a stable cross-β dominated secondary structure which allows self-assembly, leading to insoluble oligomers and lastly to fibrils. These highly ordered protein aggregates have been, for a long time, mainly associated with human neurodegenerative diseases such as Alzheimer’s disease (Amyloid-β peptides). However, they also exert physiological functions such as in release of deposited hormones in human beings. In the light of the rediscovery of our microbial commensals as important companions in health and disease, the fact that…

Thermostabilization of BSA in TMAO Water Mixtures by Infrared Spectroscopy

2019

Background:Trimethylamine-N-Oxide (TMAO) is a small organic molecule derived from the metabolism of L-carnitine and choline after ingestion of animal food. TMAO has many functions such as electron acceptor, an osmolyte, stabilizer of macromolecules folding. It seems that TMAO plays an important role in nature but, in humans, it is a remnant of the evolution of the osmolyte system.Objective:The present paper is addressed on the study of thermal stability of hydrated Bovine Serum Albumins (BSA) in the presence of water and TMAO water solution by means of InfraRed spectroscopy. In particular, this work has investigated the protein amide I spectral regions, which is sensitive to protein seconda…

2020

Nature is an indispensable source of new drugs, providing unique bioactive lead structures for drug discovery. In the present study, secalonic acid F (SAF), a naturally occurring ergochrome pigment, was studied for its cytotoxicity against various leukemia and multiple myeloma cells by the resazurin assay. SAF exhibited cytotoxic activity on both leukemia and multiple myeloma cells. Generally, multiple myeloma cells were more sensitive to SAF than leukemia cells. NCI-H929 cells were the most affected cells among the tested panel of multiple myeloma cell lines and were taken for further studies to assess the mode of action of SAF on those cells. Cell cycle analysis revealed that SAF induced …

NMR Exchange Format: a unified and open standard for representation of NMR restraint data

2015

SCOPUS: le.j

Mineral profiles of legumes and fruits through partial least squares energy dispersive X-ray fluorescence

2019

Abstarct Energy dispersive X-ray fluorescence (ED-XRF) has been employed for the determination of mineral elements in 15 varieties of legumes and 14 cherry samples. ED-XRF signals directly obtained from pulverized samples were modelized by partial least squares (PLS) using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) of a selected number of samples, after microwave assisted acid digestion, as reference data. Models were built to predict the concentration of Al, Ca, Cu, Fe, K, Mg, P, Sr and Zn. Average concentrations predicted were 6, 930, 7, 40, 6400, 990, 2100, 4 and 15 μg g−1 for Al, Ca, Cu, Fe, K, Mg, P, Sr and Zn, respectively with relative errors from 7 till 26%. …

Problems in time-intensity measurements. A case study-Bitterness evaluation in water solutions and in beers

1992

International audience

Experimental virus evolution in cancer cell monolayers, spheroids, and tissue explants

2021

Viral laboratory evolution has been used for different applications, such as modeling viral emergence, drug-resistance prediction, and therapeutic virus optimization. However, these studies have been mainly performed in cell monolayers, a highly simplified environment, raising concerns about their applicability and relevance. To address this, we compared the evolution of a model virus in monolayers, spheroids, and tissue explants. We performed this analysis in the context of cancer virotherapy by performing serial transfers of an oncolytic vesicular stomatitis virus (VSV-Δ51) in 4T1 mouse mammary tumor cells. We found that VSV-Δ51 gained fitness in each of these three culture systems, and t…

Modeling of Particle Number Fluctuations in Entire Cells

2012

In a recent study we developed a method to model protein diffusion in cells [1], where special attention was given to generating from image data of the measured cell a realistic digital model cell in which protein dynamics were simulated. The method was shown to be well suited for modeling non-equilibrium situations that arise, e.g., in photobleaching experiments, and to be capable of producing more detailed information about protein motion than traditional modeling.Another experimental way to assess protein dynamics is to study fluctuations in the local protein number, as it is done, e.g., in fluorescence correlation spectroscopy (FCS), or in similar measurements that apply single-plane il…