scholarly journals BioLogic, a parallel approach to cell-based logic gates

2018 ◽  
Author(s):  
Felipe A. Millacura ◽  
Brendan Largey ◽  
Christopher E. French
Keyword(s):  
Escherichia Coli ◽  
Genetic Engineering ◽  
Logic Gates ◽  
Full Adder ◽  
Complex Processes ◽  
First Time ◽  
Logic System

Abstract:In vivo logic gates have proven difficult to combine into larger devices. Our cell-based logic system, BioLogic, decomposes a large circuit into a collection of small subcircuits working in parallel, each subcircuit responding to a different combination of inputs. A final global output is then generated by a combination of the responses. Using BioLogic, for the first time a completely functional 3-bit full adder and full subtractor were generated using Escherichia coli cells; as well as a calculator-style display that shows a numeric result, from 0 to 7, when the proper 3 bit binary inputs are introduced into the system. BioLogic demonstrates the use of a parallel approach for the design of cell-based logic gates that facilitates the generation and analysis of complex processes, without the need for complex genetic engineering.

scholarly journals Influence of High Pressure on the Dimerization of ToxR, a Protein Involved in Bacterial Signal Transduction

2008 ◽  
Vol 74 (24) ◽  
pp. 7821-7823 ◽  
Author(s):  
Kai Linke ◽  
Nagarajan Periasamy ◽  
Matthias Ehrmann ◽  
Roland Winter ◽  
Rudi F. Vogel
Keyword(s):  
Escherichia Coli ◽  
Signal Transduction ◽  
High Pressure ◽  
Structure And Function ◽  
Transmembrane Segments ◽  
Bacterial Signal Transduction ◽  
Reporter Strains ◽  
And Function ◽  
First Time

ABSTRACT High hydrostatic pressure (HHP) is suggested to influence the structure and function of membranes and/or integrated proteins. We demonstrate for the first time HHP-induced dimer dissociation of membrane proteins in vivo with Vibrio cholerae ToxR variants in Escherichia coli reporter strains carrying ctx::lacZ fusions. Dimerization ceased at 20 to 50 MPa depending on the nature of the transmembrane segments rather than on changes in the ToxR lipid bilayer environment.

scholarly journals Thermodynamic aspects of the self-assembly of DsrA, a small noncoding RNA from Escherichia coli.

2014 ◽  
Vol 61 (1) ◽  
Author(s):  
Frédéric Geinguenaud ◽  
Maeva Gesson ◽  
Véronique Arluison
Keyword(s):  
Escherichia Coli ◽  
Self Assembly ◽  
Noncoding Rna ◽  
The Self ◽  
Functional Consequence ◽  
Small Noncoding Rna ◽  
The Difference ◽  
First Time ◽  
Thermodynamic Basis

DsrA is an Escherichia coli small noncoding RNA that acts by base pairing to some mRNAs in order to control their translation and turnover. It was recently shown that DsrA is able to self-associate in a way similar to DNA and to build nanostructures. Although functional consequence of this RNA self-assembly in vivo is not yet understood, the formation of such an assemblage more than likely influences the noncoding RNA function. We report here for the first time the thermodynamic basis of this natural RNA self-assembly. In particular we show that assembling of the ribonucleic acid is enthalpy driven and that the versatility of the RNA molecule is important for the polymerisation; indeed, an equivalent DNA sequence is unable to make a nanoassembly. The origin of the difference is discussed herein.

Genetic engineering of Escherichia coli for the production of precorrin-3 in vivo and in vitro

1999 ◽  
Vol 7 (10) ◽  
pp. 2215-2219 ◽  
Author(s):  
Charles A. Roessner ◽  
Jeong-Ho Park ◽  
A.Ian Scott
Keyword(s):  
Escherichia Coli ◽  
Genetic Engineering

scholarly journals Violaxanthin conversion by recombinant diatom and plant de-epoxidases, expressed in Escherichia coli – comparative analysis

2019 ◽  
Author(s):  
Monika Olchawa-Pajor ◽  
Monika Bojko ◽  
Wojciech Strzałka ◽  
Kazimierz Strzałka ◽  
Dariusz Latowski
Keyword(s):  
Escherichia Coli ◽  
Open Reading Frames ◽  
Amino Acid Residues ◽  
Metal Affinity ◽  
Comparable Activity ◽  
First Time ◽  
Kinetics Of ◽  
Reading Frames

The purpose of this research was to obtain recombinant violaxanthin de-epoxidases (VDEs) from two species. The first one was VDE of Arabidopsis thaliana (L.) Heynh. (WT Columbia strain) (AtVDE) which in vivo catalyzes conversion of violaxanthin (Vx) to zeaxanthin (Zx) via anteraxanthin (Ax). The second one was VDE of Phaeodactylum tricornutum Bohlin, 1897 (CCAP 1055/1 strain) (PtVDE) which is responsible for de-epoxidation of diadinoxanthin (Ddx) to diatoxanthin (Dtx). As the first step of our experiments, open reading frames coding for studied enzymes were amplified and subsequently cloned into pET-15b plasmid. For recombinant proteins production Escherichia coli Origami b strain was used. The molecular weight of the produced enzymes were estimated approximately at 45kDa and 50kDa for AtVDE and PtVDE, respectively. Both enzymes, purified under native conditions by immobilized metal affinity chromatography, displayed comparable activity in assay mixture and converted up to 90% Vx in 10 min in two steps enzymatic de-epoxidation, irrespective of enzyme origin. No statistically significant differences were observed when kinetics of the reactions catalyzed by these enzymes were compared. Putative role of selected amino-acid residues of AtVDE and PtVDE was also considered. The significance of the first time obtained recombinant PtVDE as a useful tool in various comparative investigations of de-epoxidation reactions in main types of xanthophyll cycles existing in nature are also indicated.

scholarly journals Characterization of the Contribution to Virulence of Three Large Plasmids of Avian Pathogenic Escherichia coli χ7122 (O78:K80:H9)

2010 ◽  
Vol 78 (4) ◽  
pp. 1528-1541 ◽  
Author(s):  
Melha Mellata ◽  
Keith Ameiss ◽  
Hua Mo ◽  
Roy Curtiss
Keyword(s):  
Escherichia Coli ◽  
Control Strategies ◽  
Animal Health ◽  
Pathogenic Escherichia Coli ◽  
In The Wild ◽  
Large Plasmids ◽  
Different Strains ◽  
First Time

ABSTRACT Despite the fact that the presence of multiple large plasmids is a defining feature of extraintestinal pathogenic Escherichia coli (ExPEC), such as avian pathogenic E. coli (APEC), and despite the fact that these bacteria pose a considerable threat to both human and animal health, characterization of these plasmids is still limited. In this study, after successfully curing APEC of its plasmids, we were able to investigate, for the first time, the contribution to virulence of three plasmids, pAPEC-1 (103 kb), pAPEC-2 (90 kb), and pAPEC-3 (60 kb), from APEC strain χ7122 individually as well as in all combinations in the wild-type background. Characterization of the different strains revealed unique features of APEC virulence. In vivo assays showed that curing the three plasmids resulted in severe attenuation of virulence. The presence of different plasmids and combinations of plasmids resulted in strains with different pathotypes and levels of virulence, reflecting the diversity of APEC strains associated with colibacillosis in chickens. Unexpectedly, our results associated the decrease in growth of some strains in some media with the virulence of APEC, and the mechanism was associated with some combinations of plasmids that included pAPEC-1. This study provided new insights into the roles of large plasmids in the virulence, growth, and evolution of APEC by showing for the first time that both the nature of plasmids and combinations of plasmids have an effect on these phenomena. It also provided a plausible explanation for some of the conflicting results related to the virulence of ExPEC strains. This study should help us understand the virulence of other ExPEC strains and design more efficient infection control strategies.

Development of a novel bacteriophage based biomagnetic separation method as an aid for sensitive detection of viable Escherichia coli

The Analyst ◽  
2016 ◽  
Vol 141 (3) ◽  
pp. 1009-1016 ◽  
Author(s):  
Ziyuan Wang ◽  
Danhui Wang ◽  
Juhong Chen ◽  
David A. Sela ◽  
Sam R. Nugen
Keyword(s):  
Escherichia Coli ◽  
Genetic Engineering ◽  
Magnetic Beads ◽  
Separation Method ◽  
Sensitive Detection ◽  
Bacteriophage T7 ◽  
E Coli ◽  
Liquid Samples ◽  
Oriented Immobilization

Genetic engineering of bacteriophage T7 allowed thein vivobiotinylation of capsid proteins. Oriented immobilization of the phage on magnetic beads then enabled the adsorption and separation ofE. colifrom liquid samples.

scholarly journals Novel Model To Study Virulence Determinants of Escherichia coli K1

2007 ◽  
Vol 75 (12) ◽  
pp. 5735-5739 ◽  
Author(s):  
Naveed Ahmed Khan ◽  
Graham John Goldsworthy
Keyword(s):  
Escherichia Coli ◽  
Protein A ◽  
Deletion Mutants ◽  
Virulence Determinants ◽  
E Coli ◽  
K 12 ◽  
Cytotoxic Necrotizing Factor 1 ◽  
First Time ◽  
The Brain

ABSTRACT It is shown here for the first time that locusts can be used as a model to study Escherichia coli K1 pathogenesis. E. coli K-12 strain HB101 has very low pathogenicity to locusts and does not invade the locust brain, whereas the injection of 2 × 106 E. coli K1 strain RS218 (O18:K1:H7) kills almost 100% of locusts within 72 h and invades the brain within 24 h of injection. Both mortality and invasion of the brain in locusts after injection of E. coli K1 require at least two of the known virulence determinants shown for mammals. Thus, deletion mutants that lack outer membrane protein A or cytotoxic necrotizing factor 1 have reduced abilities to kill locusts and to invade the locust brain compared to the parent E. coli K1. Interestingly, deletion mutants lacking FimH or the NeuDB gene cluster are still able to cause high mortality. It is argued that the likely existence of additional virulence determinants can be investigated in vivo by using this insect system.

Безопасность соединений из группы терпенов ментанового ряда in vitro и in vivo

2020 ◽  
Vol 83 (4) ◽  
pp. 24-30
Author(s):  
Ирина Владимировна Акулина ◽  
Светлана Ивановна Павлова ◽  
Ирина Семеновна Степаненко ◽  
Назира Сунагатовна Карамова ◽  
Александр Владиславович Сергеев ◽  
...  
Keyword(s):  
Escherichia Coli

Проведено токсикологическое исследование соединений с антибактериальными свойствами из группы терпенов ментанового ряда в условиях in vitro и in vivo: лимонена (B34), его производного (+)-1,2-оксида лимонена (B60) и серосодержащего монотерпенового соединения 2-(1’-гидрокси-4’-изопренил-1’-метилциклогексил-2’-тио)метилэтаноата (B65). В условиях in vitro (культура опухолевых клеток HeLa) изучаемые монотерпены в диапазоне концентраций 2 – 200 мкг/мл обладали цитотоксичностью. Ингибирующая концентрация (ИК50) для B34 составила 231 (167 – 295) мкг/мл, для B60 – 181 (105 – 257) мкг/мл, ИК50 B65 – 229 (150 – 308) мкг/мл. Исследование генотоксичности показало, что B34 и B65 в диапазоне концентраций 50 – 1000 мкг/мл не индуцируют SOS мутагенез в клетках Escherichia coli PQ37, тогда как B60 в концентрациях 500 и 1000 мкг/мл проявляет генотоксичность. In vivo в остром эксперименте на беспородных мышах установлена низкая токсичность B34 и его производных при различных путях введения. Наименьший показатель острой токсичности имеет B65, в связи с чем дополнительно на крысах проведено изучение его хронической токсичности. Ежедневное внутрижелудочное введение B65 в разовых дозах, составляющих 1/10 и 1/20 ЛД50 (1000 мг/кг и 500 мг/кг), в течение 1 мес не вызывало гибели животных, значимых нарушений общего состояния, изменения динамики массы тела, морфопатологических изменений. Внутрижелудочное введение B65 крысам в высокой токсической дозе 2000 мг/кг (1/5 ЛД50) в течение месяца вызывает патоморфологические изменения структуры печени.

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