Dimintors: Some strains of E. coli produce heat-stable enterotoxins (ST), which are small peptides that are able to withstand heat treatment at 100 °C. receptors on the cell surface affect intracellular signaling pathways. enterotoxins bind and activate membrane-bound guanylate cyclase, intracellular accumulation of cyclic GMP. nt overload salt dys cell dysf cell det. Prion Disease mimetics/simulants/etc..
Membrane-damaging toxins exhibit hemolysin or cytolysin activity etc.
channel tox, integratory tox (post cell formation), formation modulation tox (cellular), degenerators (metabolite production, component production part, unit production complete whole, etc.)
All CDCs are secreted by the type II secretion system;[4] the exception is pneumolysin, which is released from the cytoplasm of Streptococcus pneumoniae when the bacteria lyse.
The CDCs Streptococcus pneumoniae Pneumolysin, Clostridium perfringens perfringolysin O, and Listeria monocytogenes listeriolysin O cause specific modifications of histones in the host cell nucleus, resulting in down-regulation of several genes that encode proteins involved in the inflammatory response.[5] Histone modification does not involve the pore-forming activity of the CDCs.
Pneumolysins. lysins.
https://en.wikipedia.org/wiki/Exotoxin
Pneumolysin is a putative virulence factor of the Gram-positive bacteria Streptococcus pneumoniae.[1]
It is a pore-forming toxin of 53 kDa composed of 471 amino acids.[2] It has a range of biological activity, including the ability to lyse[3] and interfere with the function of cells and soluble molecules of the immune system.[4]
Released pneumolysin will aid the bacteria during colonization, by facilitating adherence to the host,[5]during invasion by damaging host cells,[6] and during infection by interfering with the host immune response.[7]
The presence of pneumolysin in sputum,[8] urine,[9] CSF[10] and blood[11] can be indicative of an S. pneumoniae infection.
https://en.wikipedia.org/wiki/Pneumolysin
Streptococcus pyogenes is a species of Gram-positive, aerotolerant bacterium in the genus Streptococcus. These bacteria are extracellular, and made up of non-motile and non-sporing cocci. It is clinically important for humans. It is an infrequent, but usually pathogenic, part of the skin microbiota. It is the predominant species harboring the Lancefield group A antigen, and is often called group A Streptococcus (GAS). However, both Streptococcus dysgalactiae and the Streptococcus anginosusgroup can possess group A antigen. Group A streptococci when grown on blood agar typically produces small zones of beta-hemolysis, a complete destruction of red blood cells. (A zone size of 2–3 mm is typical.) It is thus also called group A (beta-hemolytic) Streptococcus (GABHS), and it can make colonies greater than 0.5 mm in size.[1]
https://en.wikipedia.org/wiki/Streptococcus_pyogenes
RTX toxins can be identified by the presence of a specific tandemly repeated nine-amino acid residue sequence in the protein. The prototype member of the RTX toxin family is haemolysin A (HlyA) of E. coli.[citation needed] RTX is also found in Legionella pneumophila.[6]
https://en.wikipedia.org/wiki/Exotoxin
Legionella pneumophila is a thin, aerobic, pleomorphic, flagellated, non-spore-forming, Gram-negative bacterium of the genus Legionella.[1][2] L. pneumophila is the primary human pathogenic bacterium in this group and is the causative agent of Legionnaires' disease, also known as legionellosis.
In nature, L. pneumophila infects freshwater and soil amoebae of the genera Acanthamoeba and Naegleria.[3] The mechanism of infection is similar in amoeba and human cells.
aerobic capable var (metabolic etc. overlap aerobic met resp cap ; no mitochondria or mitochondria - anaerobic or aerobic or both or etc. - hydrosome - hydrogen energy - mitochondria type - mitochondria or not; hydrosome hydrogen metabolism/respiration processes, energy gen by hydrogen (hydrogen decomposer; protein rep for proton; electron current/etc.; energy and processes may use hydrogen only or predom un; etc.) animals pre-mammal mammal type animal type kingdom etc..
https://en.wikipedia.org/wiki/Legionella_pneumophila
Granulomatous Amebic Encephalitis (GAE)[edit]
Granulomatous Amebic Encephalitis (GAE) is caused by amoebic infection of the central nervous system (CNS).
Amaebozoaes
https://en.wikipedia.org/wiki/Acanthamoeba
Acanthamoeba is a genus of amoebae that are commonly recovered from soil, fresh water, and other habitats. Acanthamoeba has two evolutive forms, the metabolically active trophozoite and a dormant, stress-resistant cyst. Trophozoites are small, usually 15 to 25 μm in length and amoeboid in shape. In nature, Acanthamoeba species are free-living bacterivores, but in certain situations, they can cause infections (acanthamebiasis) in humans and other animals.[1]
Infection is generally associated with underlying conditions such as immunodeficiency, diabetes, malignancies, malnutrition, systemic lupus erythematosus, and alcoholism.[1] The parasite enters the body through cuts in the skin or by being inhaled into the upper respiratory tract.[1] The parasite then spreads through the blood into the CNS. Acanthamoeba crosses the blood–brain barrierby means that are not yet understood. Subsequent invasion of the connective tissue and induction of pro-inflammatory responses leads to neuronal damage that can be fatal within days. Pure granulomatous lesions are rare in patients with AIDS and other related immunodeficiency states, as the patients do not have adequate numbers of CD+ve T-cells to mount a granulomatous response to Acanthamoeba infection in CNS and other organs and tissues.[4] A perivascular cuffing with amoebae in necrotic tissue is usual finding in the AIDS and related T-cell immunodeficiency conditions.
Brain biopsy normally reveals severe oedema and hemorrhagic necrosis.[7]
Recent publications show atropine to interfere with the protist's CHRM1 receptor, causing cell death.[9]
Atropine
Infection usually mimics that of bacterial leptomeningitis, tuberculous meningitis, or viral encephalitis. The misdiagnosis often leads to erroneous, ineffective treatment. In the case that the Acanthamoeba is diagnosed correctly, the current treatments, such as amphotericin B, rifampicin, trimethoprim-sulfamethoxazole, ketoconazole, fluconazole, sulfadiazine, or albendazole, are only tentatively successful.
Several species of bacteria that can cause human disease are also able to infect and replicate within Acanthamoeba species.[1] These include Legionella pneumophila, Pseudomonas aeruginosa, and some strains of Escherichia coli and Staphylococcus aureus.[1][15] For some of these bacteria, replication inside Acanthamoeba has been associated with enhanced growth in macrophages, and increased resistance to some antibiotics.[1] Furthermore, due to the high prevalence of Acanthamoeba in the environment, these amoebae have been proposed to serve as an environmental reservoir for some human pathogens.[1]
A. castellanii can be found at high densities in various soil ecosystems. It preys on bacteria, but also fungi and other protozoa.
This species is able to lyse bacteria and produce a wide range of enzymes, such as cellulases or chitinases,[16] and probably contributes to the breakdown of organic matter in soil, contributing to the microbial loop.
Because Acanthamoeba does not differ greatly at the ultrastructural level from a mammalian cell, it is an attractive model for cell-biology studies; it is important in cellular microbiology, environmental biology, physiology, cellular interactions, molecular biology, biochemistry, and evolutionary studies, due to the organisms' versatile roles in the ecosystem and ability to capture prey by phagocytosis, act as vectors and reservoirs for microbial pathogens, and to produce serious human infections. In addition, Acanthamoeba has been used extensively to understand the molecular biology of cell motility[17] and cancer cell dormancy by in-depth exploration of the process of encystation.[18]
Acanthamoeba also has served as a model to study the evolution of certain G-proteins. This unicellular eukaryote expresses few GPCRs over its cell membrane that serve vital role for the microorganism, structural homology bioinformatics tools have been used to show the presence of a homolog of human M1-muscarinic receptor in A. castellanii.[20] Blocking these muscarinic receptors in past studies has proven to be amoebicidal in Acanthamoeba spp.[5] More recently, voltage-gated calcium channels in Acanthamoeba spp. (CavAc) have been reported to have similarities with human voltage-gated calcium channels such as TPC-1 and L-type calcium channels and respond to Ca-channel blockers such as loperamide.[21] This model microbe has been studied to understand complex neurodegenerative states including Alzheimer's disease. Scientists have isolated a neurotransmitter acetylcholine in Acanthamoeba and the enzymatic machinery needed for its synthesis.[22]
The giant viruses Mimivirus, Megavirus, and Pandoravirus infect Acanthamoeba.[25]
Members of the genus Acanthamoeba are unusual in serving as hosts for a variety of giant viruses (that have more than 1000 protein-coding genes; for instance, Pandoravirus, which has about 2500 protein-coding genes in its genome).
https://en.wikipedia.org/wiki/Acanthamoeba
Amoeba
Amoebas (Subphylum Sarcodina) are either naked or shelled, with the encased or testate amoebae largely inhabiting freshwater and moist soils.
From: Encyclopedia of Forest Sciences, 2004
Related terms:
Genus
Enzymes
Fungi
Parasites
Mutation
Proteins
DNA
Protozoa
View all Topics
https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/amoeba
An amoeba (/əˈmiːbə/; less commonly spelt ameba or amœba; plural am(o)ebas or am(o)ebae /əˈmiːbi/),[1] often called an amoeboid, is a type of cell or unicellular organism which has the ability to alter its shape, primarily by extending and retracting pseudopods.[2] Amoebae do not form a single taxonomic group; instead, they are found in every major lineage of eukaryotic organisms. Amoeboid cells occur not only among the protozoa, but also in fungi, algae, and animals.[3][4][5][6][7]
Microbiologists often use the terms "amoeboid" and "amoeba" interchangeably for any organism that exhibits amoeboid movement.[8][9]
In older classification systems, most amoebae were placed in the class or subphylumSarcodina, a grouping of single-celled organisms that possess pseudopods or move by protoplasmic flow. However, molecular phylogenetic studies have shown that Sarcodina is not a monophyletic group whose members share common descent. Consequently, amoeboid organisms are no longer classified together in one group.[10]
The best known amoeboid protists are Chaos carolinense and Amoeba proteus, both of which have been widely cultivated and studied in classrooms and laboratories.[11][12] Other well known species include the so-called "brain-eating amoeba" Naegleria fowleri, the intestinal parasite Entamoeba histolytica, which causes amoebic dysentery, and the multicellular "social amoeba" or slime mouldDictyostelium discoideum.
https://en.wikipedia.org/wiki/Amoeba
Free-living amoebae may be "testate" (enclosed within a hard shell), or "naked" (also known as gymnamoebae, lacking any hard covering). The shells of testate amoebae may be composed of various substances, including calcium, silica, chitin, or agglutinations of found materials like small grains of sand and the frustules of diatoms.[15]
https://en.wikipedia.org/wiki/Amoeba
A frustule is the hard and porous cell wall or external layer of diatoms. The frustule is composed almost purely of silica, made from silicic acid, and is coated with a layer of organic substance, which was referred to in the early literature on diatoms as pectin, a fiber most commonly found in cell walls of plants.[1][2] This layer is actually composed of several types of polysaccharides.[3]
https://en.wikipedia.org/wiki/Frustule
Diatoms (diá-tom-os 'cut in half', from diá, 'through' or 'apart', and the root of tém-n-ō, 'I cut')[6]are a major group of algae,[7] specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a significant portion of the Earth's biomass: they generate about 20 to 50 percent of the oxygen produced on the planet each year,[8][9] take in over 6.7 billion metric tons of silicon each year from the waters in which they live,[10] and constitute nearly half of the organic material found in the oceans. The shells of dead diatoms can reach as much as a half-mile (800 m) deep on the ocean floor, and the entire Amazon basin is fertilized annually by 27 million tons of diatom shell dust transported by transatlantic winds from the African Sahara, much of it from the Bodélé Depression, which was once made up of a system of fresh-water lakes.[11][12]
https://en.wikipedia.org/wiki/Diatom
The genome sequence of Naegleria gruberi (Fritz-Laylin et al. 2010) and published ESTs from Acanthamoeba castellanii(Hug et al. 2010) each provide a strong prediction of an ability to toggle between aerobic and anaerobic modes of metabolism. The physiological interplay between aerobic and anaerobic modes of ATP production has been studied more extensively in the chlorophyte alga Chlamydomonas reinhardtii. Distributed worldwide, this ubiquitous alga is found in a diversity of aquatic, soil and forest environments (Harris 2009). Known more for growing as a photoautotroph, Chlamydomonas nonetheless responds to dark anaerobic conditions by fermenting the plastidic starch that accumulates in the light (Kreuzberg 1984; Mus et al. 2007; Posewitz et al. 2004). In laboratory-grown algae, the end-products of fermentation are formaldehyde, acetate, ethanol, and H2, plus a little malate (Gfeller and Gibbs 1984; Kreuzberg 1984; Mus et al. 2007).
https://www.sciencedirect.com/topics/immunology-and-microbiology/naegleria-gruberi
Enzymatic chokepoints and synergistic drug targets in the sterol biosynthesis pathway of Naegleria fowleri
Wenxu Zhou ,
Anjan Debnath ,
Gareth Jennings,
Hye Jee Hahn,
Boden H. Vanderloop,
Minu Chaudhuri,
W. David Nes,
Larissa M. Podust
Published: September 13, 2018
https://doi.org/10.1371/journal.ppat.1007245
Naegleria fowleri is a free-living amoeba that can also act as an opportunistic pathogen causing severe brain infection, primary amebic meningoencephalitis (PAM), in humans. The high mortality rate of PAM (exceeding 97%) is attributed to (i) delayed diagnosis, (ii) lack of safe and effective anti-N. fowleri drugs, and (iii) difficulty of delivering drugs to the brain. Our work addresses identification of new molecular targets that may link anti-Naegleria drug discovery to the existing pharmacopeia of brain-penetrant drugs. Using inhibitors with known mechanism of action as molecular probes, we mapped the sterol biosynthesis pathway of N. fowleri by GC-MS analysis of metabolites. Based on this analysis, we chemically validated two enzymes downstream to CYP51, sterol C24-methyltransferase (SMT, ERG6) and sterol Δ8−Δ7 -isomerase (ERG2), as potential therapeutic drug targets in N. fowleri. The sterol biosynthetic cascade in N. fowleri displayed a mixture of canonical features peculiar to different domains of life: lower eukaryotes, plants and vertebrates. In addition to the cycloartenol→ergosterol biosynthetic route, a route leading to de novo cholesterol biosynthesis emerged. Isotopic labeling of the de novo-synthesized sterols by feeding N. gruberi trophozoites on the U13C-glucose-containing growth medium identified an exogenous origin of cholesterol, while 7-dehydrocholesterol (7DHC) had enriched 13C-content, suggesting a dual origin of this metabolite both from de novo biosynthesis and metabolism of scavenged cholesterol. Sterol homeostasis in Naegleria may be orchestrated over the course of its life-cycle by a “switch” between ergosterol and cholesterol biosynthesis. By demonstrating the growth inhibition and synergistic effects of the sterol biosynthesis inhibitors, we validated new, potentially druggable, molecular targets in N. fowleri. The similarity of the Naegleria sterol Δ8−Δ7 -isomerase to the human non-opioid σ1 receptor, implicated in human CNS conditions such as addiction, amnesia, pain and depression, provides an incentive to assess structurally diverse small-molecule brain-penetrant drugs targeting the human receptor for anti-Naegleria activity.
https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1007245
Pathogen & Environment
Causal Agents:
Acanthamoeba spp. , are commonly found in lakes, swimming pools, tap water, and heating and air conditioning units. Several species of Acanthamoeba, including A. culbertsoni, A. polyphaga, A. castellanii, A. astronyxis, A. hatchetti, A. rhysodes, A. divionensis, A. lugdunensis, and A. lenticulata are implicated in human disease.
Acanthamoeba spp. have been found in soil; fresh, brackish, and sea water; sewage; swimming pools; contact lens equipment; medicinal pools; dental treatment units; dialysis machines; heating, ventilating, and air conditioning systems; mammalian cell cultures; vegetables; human nostrils and throats; and human and animal brain, skin, and lung tissues. Unlike N. fowleri, Acanthamoeba has only two stages, cysts (1) and trophozoites (2), in its life cycle. No flagellated stage exists as part of the life cycle. The trophozoites replicate by mitosis (nuclear membrane does not remain intact) (3). The trophozoites are the infective forms, although both cysts and trophozoites gain entry into the body (4) through various means. Entry can occur through the eye (5), the nasal passages to the lower respiratory tract (6), or ulcerated or broken skin (7). When Acanthamoeba spp. enters the eye it can cause severe keratitis in otherwise healthy individuals, particularly contact lens users (8). When it enters the respiratory system or through the skin, it can invade the central nervous system by hematogenous dissemination causing granulomatous amebic encephalitis (GAE) (9) or disseminated disease (10), or skin lesions (11) in individuals with compromised immune systems. Acanthamoeba spp. cysts and trophozoites are found in tissue.
Life cycle image and information courtesy of DPDx.
https://www.cdc.gov/parasites/acanthamoeba/pathogen.html
Vol. 21, No. 1, January - June, 2018 Baqai J. Health Sci.
MINI REVIEW
PRIMARY MENINGOENCEPHALITIS CAUSED BY NAEGLERIA FOWLERI: A MINI REVIEW
Hassan Bin-Asif, Syed Abid Ali*
H.E.J. Research Institute of Chemistry, International Centre for Chemical and Biological Sciences (ICCBS), University of Karachi, Karachi, Pakistan
Received: December 12, 2017 Accepted: February 15, 2018
ABSTRACT
The recent outbreak of primary meningoencephalitis caused by free-living amoebae (FLA), Naegleria fowleri, has gained increasing attention due to their confirmed fatality. It is caused by the entrance of contaminated water into nasal passage mainly by ablution practices. The symptoms include severe headache, nausea, vomiting along with fever finally leading to death. FLA other than N. fowleri such as Acanthamoeba and Balamuthia species are also harmful because they are vectors of many bacterial pathogens including Vibrio, Pseudomonas, Legionella, Enterobacter and Mycobacterium species which help them to feed and colonize in environments, thus contributing to their pathogenesis and transferability to their hosts. Pakistan, being an underdeveloped country, faces long-term shortfalls of electricity resulting in serious water scarcity leading to public dependence on stored water resources, which are breeding hubs for FLA. The rationale of the present review is to highlight the importance of N. fowleri and primary meningoencephalitis and to investigate the recent outbreak in Pakistan.
Keywords: Free-living amoeba, Naegleria fowleri, primary meningoencephalitis.
https://applications.emro.who.int/imemrf/Baqai_J_Health_Sci/Baqai_J_Health_Sci_2018_21_1_42_48.pdf
https://en.wikipedia.org/wiki/Streptococcus_pyogenes
https://en.wikipedia.org/wiki/Exotoxin
https://en.wikipedia.org/wiki/ESKAPE
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8305969/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8306300/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4768623/
08-02-2021-1350 - pgrhnhetgermneander drafting - fungus, amoebaes/protazoas/amobaezoae/etc. granulomatous encephalitis meningitis meningococcus meningosis cyst or no cyst hydrosomes hydrogen metabolism nmc/aero/anaero/? enterotixins/entertix/enteroticks/lysteriolysin/lysin/inflammation/pyogenes/perfingens/gangars/fuls/faes/legionella/voc/bbb/atrop/microbial loop/chrm1 rec/macrophage/t cell/immune upregulation/autoimmune dis/lesions/cyst/stress resistant cyst/acantha/muscar receptor/ACh NT/volt sensitive 'gated' channels/calciums/calsium/C12+/photoautotroph/asxrepro/budding/fission repro/primary amebic meningoencephalitis/expansion propogation sc/env derived sf prop/trophozoite forms mitotic replication/ invade the central nervous system by hematogenous dissemination causing granulomatous amebic encephalitis (GAE)/phagocyte/sterols/amoebae sterols/opiates/secondary metabolites/antitoxins/H2 and acid from fermentation/(base env)/etc.
Hydrozoa (hydrozoans, from ancient Greek ὕδωρ, hydōr, "water" and ζῷον, zōion, "animal") are a taxonomic class of individually very small, predatory animals, some solitary and some colonial, most living in salt water. The colonies of the colonial species can be large, and in some cases the specialized individual animals cannot survive outside the colony. A few genera within this class live in fresh water. Hydrozoans are related to jellyfish and corals and belong to the phylum Cnidaria.
Some examples of hydrozoans are the freshwater jelly (Craspedacusta sowerbyi), freshwater polyps (Hydra), Obelia, Portuguese man o' war (Physalia physalis), chondrophores (Porpitidae), "air fern" (Sertularia argentea), and pink-hearted hydroids (Tubularia).
https://en.wikipedia.org/wiki/Hydrozoa
'amoebaes are carnivorous animals' (dr. bettey dvm, est 2000s)
Myxosporea is a class of microscopic parasites, belonging to the Myxozoa clade within Cnidaria. They have a complex life cycle which comprises vegetative forms in two hosts, an aquatic invertebrate(generally an annelid) and an ectothermic vertebrate, usually a fish. Each host releases a different type of spore. The two forms of spore are so different that until relatively recently they were treated as belonging to different classes within the Myxozoa.
https://en.wikipedia.org/wiki/Myxosporea
iochimie
. 1978;60(3):297-305. doi: 10.1016/s0300-9084(78)80826-8.
Hydrogen metabolism in aerobic hydrogen-oxidizing bacteria
B Schink, H G Schlegel
PMID: 667183
DOI: 10.1016/s0300-9084(78)80826-8
Abstract
A survey on organisms able to use molecular hydrogen as electron donor in the energy-yielding process is presented. In the group of the aerobic hydrogen-oxidizing bacteria so far two types of hydrogenases have been encountered, a NAD-reducing, soluble enzyme (H2 : NAD oxidoreductase) and a membrane-bound enzyme unable to reduce pyridine nucleotides. With respect to the distribution of both types of hydrogenases three groups of hydrogen-oxidizing bacteria can be diffentiated containing (i) both types (Alcaligenes eutrophus), (ii) a soluble enzyme only (Nocardia opaca lb), and (iii) a membrane-bound hydrogenase only (majority of genera and species). The results of studies on the NAD-specific hydrogenase of A. eutrophus are summarized. Results on the solubilization and purification of the membrane-bound hydrogenase of A. eutrophus are presented in detail. The enzyme was solubilized from purified membranes by Triton X-100 and sodium desoxycholate or phospholipase D. The crude membrane extract was fractionated by ammonium sulfate precipitation and chromatography on carboxymethylcellulose at pH 5.5. The enzyme was stable in potassium phosphate buffer; it resembles the soluble enzyme with respect to stability under oxidizing conditions. Further biochemical and immunological data indicate, however, that both enzymes are different with respect to their native structure.
https://pubmed.ncbi.nlm.nih.gov/667183/
EDITORIAL article
Front. Microbiol., 30 January 2020 | https://doi.org/10.3389/fmicb.2020.00056
Editorial: Microbial Hydrogen Metabolism
https://www.frontiersin.org/articles/10.3389/fmicb.2020.00056/full
Journal of Photochemistry and Photobiology B: Biology
Volume 47, Issue 1, November 1998, Pages 1-11
Invited reviewHydrogen metabolism in organisms with oxygenic photosynthesis: hydrogenases as important regulatory devices for a proper redox poising?
Author links open overlay panelJensAppelRüdigerSchulz
https://www.sciencedirect.com/science/article/abs/pii/S1011134498001791
hydrosome
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from The Century Dictionary.
noun Same as hydrosoma
from the GNU version of the Collaborative International Dictionary of English.
noun (Zoöl.) All the zooids of a hydroid colony collectively, including the nutritive and reproductive zooids, and often other kinds.
https://www.wordnik.com/words/hydrosome
5 September 2007Hydrosomes: optically trapped water droplets as nano-containers
Kristian Helmerson, Joseph E. Reiner, Alice M. Crawford, Ana M. Jofre, Rani B. Kishore, Lori S. Goldner, Jianyong Tang, Mark E. Greene, Michael Gilson
Author Affiliations +
Proceedings Volume 6644, Optical Trapping and Optical Micromanipulation IV; 66440D (2007) https://doi.org/10.1117/12.735261
Event: NanoScience + Engineering, 2007, San Diego, California, United States
ARTICLE
CITED BY
Abstract
We demonstrate a novel technique for creating, manipulating, and combining femtoliter to attoliter volume chemical containers. Possible uses include creating controlled chemical reactions involving small quantities of reagent, and studying the dynamics of single molecules. The containers, which we call hydrosomes, are surfactant stabilized aqueous droplets in a low index-of-refraction fluorocarbon medium. The index of refraction mismatch between the container and fluorocarbon is such that individual hydrosomes can be optically trapped by single focus laser beams, i.e. optical tweezers. Previous work on single molecules usually involved the tethering of the molecule to a surface, in order to interrogate the molecule for an extended period of time. The use of hydrosomes opens up the possibility for studying free molecules, away from any perturbing surface. We show that this is indeed true in the case of quantitative FRET with RNA. Furthermore, we demonstrate the controlled fusion of two hydrosomes for studying reactions, such as DNA binding kinetics, and single molecule dynamics under non-equilibrium conditions. We also show the applicability of our technique in analytical chemistry, such as for molecule identification and sorting.
© (2007) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
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Kristian Helmerson, Joseph E. Reiner, Alice M. Crawford, Ana M. Jofre, Rani B. Kishore, Lori S. Goldner,Jianyong Tang, Mark E. Greene, and Michael Gilson "Hydrosomes: optically trapped water droplets as nano-containers", Proc. SPIE 6644, Optical Trapping and Optical Micromanipulation IV, 66440D (5 September 2007); https://doi.org/10.1117/12.735261
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https://www.spiedigitallibrary.org/conference-proceedings-of-spie/6644/66440D/Hydrosomes-optically-trapped-water-droplets-as-nano-containers/10.1117/12.735261.short?SSO=1
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