Exploitation of plant and archaeal viruses in bionanotechnology

2009 ◽  
Vol 37 (4) ◽  
pp. 665-670 ◽  
Author(s):  
David J. Evans
Keyword(s):  
The Body ◽  
Layer By Layer ◽  
Archaeal Virus ◽  
Sulfolobus Islandicus ◽  
Naturally Occurring ◽  
Archaeal Viruses ◽  
Nanobuilding Blocks ◽  
Multiple Copies ◽  
Site Selective ◽  
Virion Surface

CPMV (cowpea mosaic virus), a plant virus, is a naturally occurring sphere-like nanoparticle, and is used as a synthon and/or template in bionanoscience. The virions formed by CPMV can be regarded as programmable nanobuilding blocks with a diameter of ∼30 nm. A range of molecules have been attached to this viral nanoscaffold, yielding stable nanoparticles that display multiple copies of the desired molecule. It has been shown that, in addition to surface amine groups, surface carboxy groups are also addressable, and a procedure has been developed that enables introduction of reactive thiols at the virion surface that avoids virus aggregation. Furthermore, the virions can be functionalized to form electroactive nanoparticles. Methods for the construction of arrays and multilayers, using a layer-by-layer approach, have been established. As proof of concept, for example, CPMV particles have been immobilized on surfaces and arranged in defined layers. Engineered variants of CPMV can be used as templates for mineralization with, for example, silica to give monodisperse robust silica nanoparticles of ∼32 nm. SIRV2 (Sulfolobus islandicus rod-shaped virus 2), is a robust archaeal virus, resistant to high temperature and low pH. SIRV2 can act as a template for site-selective and spatially controlled chemical modification. Both the ends and the body of the virus, or the ends only, can be chemically addressed; SIRV2 can be regarded as a structurally unique nanobuilding block.

scholarly journals A filamentous archaeal virus is enveloped inside the cell and released through pyramidal portals

2021 ◽  
Vol 118 (32) ◽  
pp. e2105540118
Author(s):  
Diana P. Baquero ◽  
Anastasia D. Gazi ◽  
Martin Sachse ◽  
Junfeng Liu ◽  
Christine Schmitt ◽  
...  
Keyword(s):  
Life Cycle ◽  
Electron Tomography ◽  
Hexagonal Lattice ◽  
Hyperthermophilic Archaea ◽  
Cell Diameter ◽  
Archaeal Virus ◽  
Host Interactions ◽  
Host Interaction ◽  
Sulfolobus Islandicus ◽  
Multiple Copies

The majority of viruses infecting hyperthermophilic archaea display unique virion architectures and are evolutionarily unrelated to viruses of bacteria and eukaryotes. The lack of relationships to other known viruses suggests that the mechanisms of virus–host interaction in Archaea are also likely to be distinct. To gain insights into archaeal virus–host interactions, we studied the life cycle of the enveloped, ∼2-μm-long Sulfolobus islandicus filamentous virus (SIFV), a member of the family Lipothrixviridae infecting a hyperthermophilic and acidophilic archaeon Saccharolobus islandicus LAL14/1. Using dual-axis electron tomography and convolutional neural network analysis, we characterize the life cycle of SIFV and show that the virions, which are nearly two times longer than the host cell diameter, are assembled in the cell cytoplasm, forming twisted virion bundles organized on a nonperfect hexagonal lattice. Remarkably, our results indicate that envelopment of the helical nucleocapsids takes place inside the cell rather than by budding as in the case of most other known enveloped viruses. The mature virions are released from the cell through large (up to 220 nm in diameter), six-sided pyramidal portals, which are built from multiple copies of a single 89-amino-acid-long viral protein gp43. The overexpression of this protein in Escherichia coli leads to pyramid formation in the bacterial membrane. Collectively, our results provide insights into the assembly and release of enveloped filamentous viruses and illuminate the evolution of virus–host interactions in Archaea.

scholarly journals The Single-Stranded DNA Genome of Novel Archaeal Virus Halorubrum Pleomorphic Virus 1 Is Enclosed in the Envelope Decorated with Glycoprotein Spikes

2009 ◽  
Vol 84 (2) ◽  
pp. 788-798 ◽  
Author(s):  
Maija K. Pietilä ◽  
Simonas Laurinavičius ◽  
Jukka Sund ◽  
Elina Roine ◽  
Dennis H. Bamford
Keyword(s):  
High Salinity ◽  
Membrane Vesicle ◽  
Structural Protein ◽  
Archaeal Virus ◽  
Host Cell Membrane ◽  
Single Stranded Dna ◽  
Enveloped Viruses ◽  
Major Structural Protein ◽  
Archaeal Viruses ◽  
Virion Surface

ABSTRACT Only a few archaeal viruses have been subjected to detailed structural analyses. Major obstacles have been the extreme conditions such as high salinity or temperature needed for the propagation of these viruses. In addition, unusual morphotypes of many archaeal viruses have made it difficult to obtain further information on virion architectures. We used controlled virion dissociation to reveal the structural organization of Halorubrum pleomorphic virus 1 (HRPV-1) infecting an extremely halophilic archaeal host. The single-stranded DNA genome is enclosed in a pleomorphic membrane vesicle without detected nucleoproteins. VP4, the larger major structural protein of HRPV-1, forms glycosylated spikes on the virion surface and VP3, the smaller major structural protein, resides on the inner surface of the membrane vesicle. Together, these proteins organize the structure of the membrane vesicle. Quantitative lipid comparison of HRPV-1 and its host Halorubrum sp. revealed that HRPV-1 acquires lipids nonselectively from the host cell membrane, which is typical of pleomorphic enveloped viruses.

Stress management: Corpus-based insights into vernacular interpretations of stress

2014 ◽  
Vol 10 (1) ◽  
pp. 81-93
Author(s):  
Laurel Smith Stvan
Keyword(s):  
Traumatic Stress ◽  
American English ◽  
Physical Symptom ◽  
The Body ◽  
Post Traumatic Stress ◽  
The Past ◽  
Academic Texts ◽  
Naturally Occurring ◽  
Post Traumatic ◽  
Semantic Shift

Examination of the term stress in naturally occurring vernacular prose provides evidence of three separate senses being conflated. A corpus analysis of 818 instances of stress from non-academic texts in the Corpus of Contemporary American English (COCA) and the Corpus of American Discourses on Health (CADOH) shows a negative prosody for stress, which is portrayed variously as a source outside the body, a physical symptom within the body and an emotional state. The data show that contemporary speakers intermingle the three senses, making more difficult a discussion between doctors and patients of ways to ‘reduce stress’, when stress might be interpreted as a stressor, a symptom, or state of anxiety. This conflation of senses reinforces the impression that stress is pervasive and increasing. In addition, a semantic shift is also refining a new sense for stress, as post-traumatic stress develops as a specific subtype of emotional stress whose use has increased in circulation in the past 20 years.

scholarly journals Could radical pairs play a role in xenon-induced general anesthesia?

2020 ◽  
Author(s):  
Jordan Smith ◽  
Hadi Zadeh Haghighi ◽  
Christoph Simon
Keyword(s):  
General Anesthesia ◽  
Radical Pair ◽  
The Body ◽  
Radical Pair Mechanism ◽  
General Anesthetic ◽  
Radical Pairs ◽  
Naturally Occurring ◽  
Isotopic Dependence ◽  
Anesthetic Potency ◽  
Recombination Dynamics

ABSTRACTUnderstanding the mechanisms underlying anesthesia would be a key step towards understanding consciousness. The process of xenon-induced general anesthesia has been shown to involve electron transfer, and the potency of xenon as a general anesthetic exhibits isotopic dependence. We propose that these observations can be explained by a mechanism in which the xenon nuclear spin influences the recombination dynamics of a naturally occurring radical pair of electrons. We develop a simple model inspired by the body of work on the radical-pair mechanism in cryptochrome in the context of avian magnetoreception, and we show that our model can reproduce the observed isotopic dependence of the general anesthetic potency of xenon in mice. Our results are consistent with the idea that radical pairs of electrons with entangled spins could be important for consciousness.

scholarly journals Body Meets Space. Space Becomes Dress.

2021 ◽  
Author(s):  
Sarah Lipsit
Keyword(s):  
Sensory Experience ◽  
The Body ◽  
The Other ◽  
Layer By Layer ◽  
The World ◽  
Soft Architecture

Forming. Shifting. Shaping. The envelope of one’s physiological body extends outwards in multiple shells, layer by layer. The versions of this envelope exist in the interstitial moment between clothing and architecture; ever forming and being formed, they shift and shape the circulation and happenings of the body on one side and the world on the other. The study of garments lends architecture recognition of various visible and invisible forces that create space and envelope. When space becomes dress, body specificity and movement is emphasized, and the geometries of the physiological body and what it means to experience space as an individual becomes primary, achieving a qualitative, sensory experience extending from the powers of kinaesthetic sense. Oscillating between scales and acts of making, model experimentation invents new ways to conceive and create architecture — a soft architecture finds itself operating here: on the liminal edge of body, envelope, and space

Coordinated righting behaviour in locusts

2001 ◽  
Vol 204 (4) ◽  
pp. 637-648 ◽  
Author(s):  
A.A. Faisal ◽  
T. Matheson
Keyword(s):  
Driving Force ◽  
Flat Surface ◽  
Longitudinal Axis ◽  
Upright Position ◽  
The Body ◽  
The Other ◽  
Legged Robots ◽  
Naturally Occurring ◽  
Key Features ◽  
Low Levels

A locust placed upside down on a flat surface uses a predictable sequence of leg movements to right itself. To analyse this behaviour, we made use of a naturally occurring state of quiescence (thanatosis) to position locusts in a standardised upside-down position from which they spontaneously right themselves. Locusts grasped around the pronotum enter a state of thanatosis during which the limbs can be manipulated into particular postures, where they remain, and the animal can be placed upside down on the ground. When released, thanatosis lasts 4–456 s (mean 73 s) before the animal suddenly becomes active again and rights itself within a further 600 ms. Thanatosis is characterised by very low levels of leg motor activity. During righting, one hind leg provides most of the downward force against the ground that rolls the body around a longitudinal axis towards the other side. The driving force is produced by femoral levation (relative to the body) at the trochanter and by tibial extension. As the animal rolls over, the hind leg on the other side is also levated at the trochanter, so that it does not obstruct the movement. The forelegs and middle legs are not required for successful righting but they can help initially to tip the locust to one side, and at the end of the movement they help stop the roll as the animal turns upright. Individual locusts have a preferred righting direction but can, nevertheless, roll to either side. Locusts falling upside down through the air use both passive and active mechanisms to right themselves before they land. Without active movements, falling locusts tend to rotate into an upright position, but most locusts extend their hind leg tibiae and/or spread their wings, which increases the success of mid-air righting from 28 to 49 % when falling from 30 cm. The rapid and reliable righting behaviour of locusts reduces the time spent in a vulnerable upside-down position. Their narrow body geometry, large hind legs, which can generate substantial dorsally directed force, and the particular patterns of coordinated movements of the legs on both sides of the body are the key features that permit locusts to right themselves effectively. The reliability of autonomous multi-legged robots may be enhanced by incorporating these features into their design.

scholarly journals Plastic, nutrition and pollution; relationships between ingested plastic and metal concentrations in the livers of two Pachyptila seabirds

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lauren Roman ◽  
Farzana Kastury ◽  
Sophie Petit ◽  
Rina Aleman ◽  
Chris Wilcox ◽  
...  
Keyword(s):  
Health Hazard ◽  
Dietary Exposure ◽  
The Body ◽  
Free Living ◽  
Seabird Species ◽  
Significant Relationships ◽  
Naturally Occurring ◽  
Plastic Metal ◽  
Liver Concentration ◽  
New Evidence

Abstract Naturally occurring metals and metalloids [metal(loid)s] are essential for the physiological functioning of wildlife; however, environmental contamination by metal(loid) and plastic pollutants is a health hazard. Metal(loid)s may interact with plastic in the environment and there is mixed evidence about whether plastic ingested by wildlife affects metal(loid) absorption/assimilation and concentration in the body. We examined ingested plastic and liver concentration of eleven metal(loid)s in two seabird species: fairy (Pachyptila turtur) and slender-billed prions (P. belcheri). We found significant relationships between ingested plastic and the concentrations of aluminium (Al), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu) and zinc (Zn) in the liver of prions. We investigated whether the pattern of significant relationships reflected plastic-metal(loid) associations predicted in the scientific literature, including by transfer of metals from ingested plastics or malnutrition due to dietary dilution by plastics in the gut. We found some support for both associations, suggesting that ingested plastic may be connected with dietary dilution / lack of essential nutrients, especially iron, and potential transfer of zinc. We did not find a relationship between plastic and non-essential metal(loid)s, including lead. The effect of plastic was minor compared to that of dietary exposure to metal(oid)s, and small plastic loads (< 3 items) had no discernible link with metal(loid)s. This new evidence shows a relationship between plastic ingestion and liver metal(loid) concentrations in free-living wildlife.

scholarly journals ORF4 of the Temperate Archaeal Virus SNJ1 Governs the Lysis-Lysogeny Switch and Superinfection Immunity

2020 ◽  
Vol 94 (16) ◽  
Author(s):  
Beibei Chen ◽  
Zhao Chen ◽  
Yuchen Wang ◽  
Han Gong ◽  
Linshan Sima ◽  
...  
Keyword(s):  
Life Cycle ◽  
Bioinformatic Analysis ◽  
Model System ◽  
Life Cycles ◽  
Host Cells ◽  
Biological Functions ◽  
Mechanistic Studies ◽  
Cultivation Conditions ◽  
Archaeal Virus ◽  
Archaeal Viruses

ABSTRACT Recent environmental and metagenomic studies have considerably increased the repertoire of archaeal viruses and suggested that they play important roles in nutrient cycling in the biosphere. However, very little is known about how they regulate their life cycles and interact with their hosts. Here, we report that the life cycle of the temperate haloarchaeal virus SNJ1 is controlled by the product ORF4, a small protein belonging to the antitoxin MazE superfamily. We show that ORF4 controls the lysis-lysogeny switch of SNJ1 and mediates superinfection immunity by repression of genomic DNA replication of the superinfecting viruses. Bioinformatic analysis shows that ORF4 is highly conserved in two SNJ1-like proviruses, suggesting that the mechanisms for lysis-lysogeny switch and superinfection immunity are conserved in this group of viruses. As the lysis-lysogeny switch and superinfection immunity of archaeal viruses have been poorly studied, we suggest that SNJ1 could serve as a model system to study these processes. IMPORTANCE Archaeal viruses are important parts of the virosphere. Understanding how they regulate their life cycles and interact with host cells provide crucial insights into their biological functions and the evolutionary histories of viruses. However, mechanistic studies of the life cycle of archaeal viruses are scarce due to a lack of genetic tools and demanding cultivation conditions. Here, we discover that the temperate haloarchaeal virus SNJ1, which infects Natrinema sp. strain J7, employs a lysis-lysogeny switch and establishes superinfection immunity like bacteriophages. We show that its ORF4 is critical for both processes and acts as a repressor of the replication of SNJ1. These results establish ORF4 as a master regulator of SNJ1 life cycle and provides novel insights on the regulation of life cycles by temperate archaeal viruses and on their interactions with host cells.

scholarly journals Hg2+ Optical Fiber Sensor Based on LSPR Generated by Gold Nanoparticles Embedded in LBL Nano-Assembled Coatings

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4906 ◽  
Author(s):  
María Elena Martínez-Hernández ◽  
Javier Goicoechea ◽  
Francisco J. Arregui
Keyword(s):  
Gold Nanoparticles ◽  
Optical Fiber Sensor ◽  
The Body ◽  
Fiber Optic Sensor ◽  
Localized Surface Plasmon ◽  
Layer By Layer ◽  
Localized Surface Plasmon Resonances ◽  
Highly Sensitive ◽  
Assembly Technique

Mercury is an important contaminant since it is accumulated in the body of living beings, and very small concentrations are very dangerous in the long term. This paper reports the fabrication of a highly sensitive fiber optic sensor using the layer-by-layer nano-assembly technique with gold nanoparticles (AuNPs). The gold nanoparticles were obtained via a water-based synthesis route that use poly acrylic acid (PAA) as stabilizing agent, in the presence of a borane dimethylamine complex (DMAB) as reducing agent, giving PAA-capped AuNPs. The sensing mechanism is based on the alteration of the Localized Surface Plasmon Resonances (LSPR) generated by AuNPs thanks to the strong chemical affinity of metallic mercury towards gold, which lead to amalgam alloys.

Sign in / Sign up

Export Citation Format

Share Document