| loss of the actin-like protein mamk has pleiotropic effects on magnetosome formation and chain assembly in magnetospirillum gryphiswaldense. | magnetotactic bacteria synthesize magnetosomes, which are unique organelles consisting of membrane-enclosed magnetite crystals. for magnetic orientation individual magnetosome particles are assembled into well-organized chains. the actin-like mamk and the acidic mamj proteins were previously implicated in chain assembly. while mamk was suggested to form magnetosome-associated cytoskeletal filaments, mamj is assumed to attach the magnetosome vesicles to these structures. although the deletion of ... | 2010 | 20487281 |
| magnetospirillum bellicus sp. nov., a novel dissimilatory perchlorate-reducing alphaproteobacterium isolated from a bioelectrical reactor. | previously isolated dissimilatory perchlorate-reducing bacteria (dprb) have been primarily affiliated with the betaproteobacteria. enrichments from the cathodic chamber of a bioelectrical reactor (ber) inoculated from creek water in berkeley, ca, yielded a novel organism most closely related to a previously described strain, wd (99% 16s rrna gene identity). strain vdy(t) has 96% 16s rrna gene identity to both magnetospirillum gryphiswaldense and magnetospirillum magnetotacticum, and along with s ... | 2010 | 20495050 |
| deletion of a fur-like gene affects iron homeostasis and magnetosome formation in magnetospirillum gryphiswaldense. | magnetotactic bacteria synthesize specific organelles, the magnetosomes, which are membrane-enveloped crystals of the magnetic mineral magnetite (fe(3)o(4)). the biomineralization of magnetite involves the uptake and intracellular accumulation of large amounts of iron. however, it is not clear how iron uptake and biomineralization are regulated and balanced with the biochemical iron requirement and intracellular homeostasis. in this study, we identified and analyzed a homologue of the ferric upt ... | 2010 | 20562310 |
| domain reorientation and rotation of an intracellular assembly regulate conduction in kir potassium channels. | potassium channels embedded in cell membranes employ gates to regulate k+ current. while a specific constriction in the permeation pathway has historically been implicated in gating, recent reports suggest that the signature ion selectivity filter located in the outer membrane leaflet may be equally important. inwardly rectifying k+ channels also control the directionality of flow, using intracellular polyamines to stem ion efflux by a valve-like action. this study presents crystallographic evid ... | 2010 | 20564790 |
| simultaneously discrete biomineralization of magnetite and tellurium nanocrystals in magnetotactic bacteria. | magnetotactic bacteria synthesize intracellular magnetosomes comprising membrane-enveloped magnetite crystals within the cell which can be manipulated by a magnetic field. here, we report the first example of tellurium uptake and crystallization within a magnetotactic bacterial strain, magnetospirillum magneticum amb-1. these bacteria independently crystallize tellurium and magnetite within the cell. this is also highly significant as tellurite (teo(3)(2-)), an oxyanion of tellurium, is harmful ... | 2010 | 20581185 |
| crystallization and preliminary crystallographic analysis of the magnetospirillum magneticum amb-1 and m. gryphiswaldense msr-1 magnetosome-associated proteins mama. | mama is a unique magnetosome-associated protein that is predicted to contain six sequential tetratricopeptide-repeat (tpr) motifs. the tpr structural motif serves as a template for protein-protein interactions and mediates the assembly of multi-protein complexes. here, the crystallization and preliminary x-ray analysis of recombinant and purified magnetospirillum magneticum and m. gryphiswaldense mama are reported for the first time. m. gryphiswaldense mamadelta41 crystallized in the tetragonal ... | 2010 | 20606283 |
| in vivo biotinylation of bacterial magnetic particles by a truncated form of escherichia coli biotin ligase and biotin acceptor peptide. | escherichia coli biotin ligase can attach biotin molecules to a lysine residue of biotin acceptor peptide (bap), and biotinylation of particular bap-fused proteins in cells was carried out by coexpression of e. coli biotin ligase (in vivo biotinylation). this in vivo biotinylation technology has been applied for protein purification, analysis of protein localization, and protein-protein interaction in eukaryotic cells, while such studies have not been reported in bacterial cells. in this study, ... | 2010 | 20622127 |
| mamo and mame genes are essential for magnetosome crystal biomineralization in magnetospirillum gryphiswaldense msr-1. | four non-magnetic mutants of magnetospirillum gryphiswaldense strain msr-1 were isolated by transposon mutagenesis and found to contain interruption of either the mamo or mame gene within the mamab operon. studies indicated that mamo and mame genes are essential for magnetosome crystal biomineralization in msr-1. this is the first report of a single gene (mamo or mame) whose mutation affects crystal biomineralization in msr-1. | 2010 | 20674739 |
| [influence of native bacterial magnetic particles on mouse immune response]. | to study the influence of native bacterial magnetic particles on mouse immune response. | 2010 | 20687349 |
| development of cellular magnetic dipoles in magnetotactic bacteria. | magnetotactic bacteria benefit from their ability to form cellular magnetic dipoles by assembling stable single-domain ferromagnetic particles in chains as a means to navigate along earth's magnetic field lines on their way to favorable habitats. we studied the assembly of nanosized membrane-encapsulated magnetite particles (magnetosomes) by ferromagnetic resonance spectroscopy using magnetospirillum gryphiswaldense cultured in a time-resolved experimental setting. the spectroscopic data show th ... | 2010 | 20713012 |
| detection of endogenous magnetic nanoparticles with a tunnelling magneto resistance sensor. | the magnetotactic bacterium magnetospirillum sp. has been cultured and the properties of its endogenous magnetic nanoparticles characterized. electron-microscopic analyses indicate that the endogenous magnetite nanoparticles in magnetospirillum sp. are coated with a 3-4 nm thick transparent shell, forming a magnetosome. these magnetite nanoparticles had diameters of 50.9+/-13.3 nm, in good agreement with the diameter of 40.6+/-1.2 nm extracted from magnetometry. each magnetospirillum sp. bacteri ... | 2010 | 20732892 |
| cell biology of prokaryotic organelles. | mounting evidence in recent years has challenged the dogma that prokaryotes are simple and undefined cells devoid of an organized subcellular architecture. in fact, proteins once thought to be the purely eukaryotic inventions, including relatives of actin and tubulin control prokaryotic cell shape, dna segregation, and cytokinesis. similarly, compartmentalization, commonly noted as a distinguishing feature of eukaryotic cells, is also prevalent in the prokaryotic world in the form of protein-bou ... | 2010 | 20739411 |
| enhancement of magnetotactic bacterial yield in a modified msgm medium without alteration of magnetosomes properties. | magnetotactic bacteria (mtb), magnetospirillum magnetotacticum (ms-1) were successfully grown in modified magnetic spirillum growth medium (msgm) at normal laboratory environment. about five-time increase in the bacterial yield was achieved in the modified msgm medium without compromising their magnetosomes properties. transmission electron and scanning electron microscopy (tem & sem) were used for morphological study of mtb. energy dispersive analysis of x-rays (edax) and vibrating sample magne ... | 2010 | 20795371 |
| rapid separation and immunoassay for low levels of salmonella in foods using magnetosome-antibody complex and real-time fluorescence quantitative pcr. | a rapid and economical method for detecting salmonella was developed, based on a novel complex for immunomagnetic separation, which was composed of anti-salmonella polyclonal antibody (ab) and magnetosome (bacterial magnetic particle, bmp) produced by the bacterium magnetospirillum gryphiswaldense msr-1. bmp-ab complex was used to capture salmonella from pure suspensions of s. dublin, s. enteritidis, s. aesch, s. agona, s. abony and s. bareily, from mixed suspensions of s. dublin and vibrio para ... | 2010 | 20886524 |
| isolation and characterization of reyranella massiliensis gen. nov., sp. nov. from freshwater samples with an amoeba co-culture procedure. | the analysis of three water samples from two cooling towers and one river allowed us to isolate three strains of a novel alphaproteobacterium species, which is phylogenetically related to uncultured alphaproteobacteria. based upon 16s rrna gene sequence analysis and phenotypic characterization, we propose to name this new species reyranella massiliensis gen. nov, sp. nov., type strain 521t (=csur p115, =dsm 23428). the closest cultivable microorganism to this new bacterium is a member of the gen ... | 2010 | 20889765 |
| synthesis of cellular organelles containing nano-magnets stunts growth of magnetotactic bacteria. | magnetotactic bacteria are unique prokaryotes possessing the feature of cellular organelles called magnetosomes (membrane bound 40-50 nm vesicles entrapping a magnetic nano-crystal of magnetite or greigite). the obvious energetic impact of sophisticated eukaryotic-like membrane-bound organelle assembly on a presumably simpler prokaryotic system is not addressed in literature. in this work, while presenting evidence of direct coupling of carbon source consumption to synthesis of magnetosomes, we ... | 2010 | 21128392 |
| phototaxis in the magnetotactic bacterium magnetospirillum magneticum strain amb-1 is independent of magnetic fields. | magnetotactic bacteria (mtb) can rapidly relocate to optimal habitats by magneto-aerotaxis. little is known about mtb phototaxis, a response that might also aid navigation. in this study, we analyzed the relationship between phototaxis and magnetotaxis in magnetospirillum magneticum strain amb-1. magnotactic amb-1 cells migrated toward light, and migration increased with higher light intensity. this response was independent of wavelength, as amb-1 cells migrated equally toward light from 400 to ... | 2010 | 21136050 |
| efficient conjugation doxorubicin to bacterial magnetic nanoparticles via a triplex hands coupling reagent. | by using a novel triplex "hand" coupling reagent, tris-succinimidyl aminotriacetate (tsat), doxorubicin loading efficiency of bmp can be greatly enhanced in comparison with that of dual functional linkers. the drug loading ratio of doxorubicin-coupled bacterial magnetic nanoparticles produced by this method (dbmp-t) is 62%. dbmp-t disperse well, have a narrow size distribution, exhibit a high magnetic response, is sensitive to ph to facilitate drug release and are strongly cytotoxic to hepg2 and ... | 2010 | 21137755 |
| large-scale production of magnetosomes by chemostat culture of magnetospirillum gryphiswaldense at high cell density. | magnetotactic bacteria have long intrigued researchers because they synthesize intracellular nano-scale (40-100 nm) magnetic particles composed of fe3o4, termed magnetosomes. current research focuses on the molecular mechanisms of bacterial magnetosome formation and its practical applications in biotechnology and medicine. practical applications of magnetosomes are based on their ferrimagnetism, nanoscale size, narrow size distribution, dispersal ability, and membrane-bound structure. however, t ... | 2010 | 21144001 |
| magnetically actuated propulsion at low reynolds numbers: towards nanoscale control. | significant progress has been made in the fabrication of micron and sub-micron structures whose motion can be controlled in liquids under ambient conditions. the aim of many of these engineering endeavors is to be able to build and propel an artificial micro-structure that rivals the versatility of biological swimmers of similar size, e.g. motile bacterial cells. applications for such artificial "micro-bots" are envisioned to range from microrheology to targeted drug delivery and microsurgery, a ... | 2010 | 21152575 |
| mms6 protein regulates crystal morphology during nano-sized magnetite biomineralization in vivo. | biomineralization, the process by which minerals are deposited by organisms, has attracted considerable attention because this mechanism has shown great potential to inspire bottom-up material syntheses. to understand the mechanism for morphological regulation that occurs during biomineralization, many regulatory proteins have been isolated from various biominerals. however, the molecular mechanisms that regulate the morphology of biominerals remain unclear because there is a lack of in vivo evi ... | 2010 | 21169637 |
| bioengineering of bacterial magnetic particles and their applications in biotechnology. | magnetic particles have attracted much attention for their versatile uses in biotechnology, especially in medical applications. the major advantage of magnetic particles is that they can be easily manipulated by magnetic forces. magnetotactic bacteria synthesize nano-sized biomagnetites, otherwise known as bacterial magnetic particles (bacmps) that are individually enveloped by a lipid bilayer membrane. the mechanisms of bacmp synthesis have been analyzed by genomic, proteomic, and bioinformatic ... | 2010 | 21171958 |
| structural purity of magnetite nanoparticles in magnetotactic bacteria. | magnetosome biomineralization and chain formation in magnetotactic bacteria are two processes that are highly controlled at the cellular level in order to form cellular magnetic dipoles. however, even if the magnetosome chains are well characterized, controversial results about the microstructure of magnetosomes were obtained and its possible influence in the formation of the magnetic dipole is to be specified. for the first time, the microstructure of intracellular magnetosomes was investigated ... | 2011 | 21247944 |
| emcd real space maps of magnetospirillum magnetotacticum. | in this study we combine energy loss magnetic circular dichroism (emcd) and energy filtered transmission electron microscopy (eftem) to map magnetic properties of nanoparticles. we show that it is a functional tool for investigating the magnetic behaviour of bio-mineralized magnetite crystals of magnetospirillum magnetotacticum. we find that the spatial resolution of our experimental set-up is in the range of less than 2 nm. the results are compared with emcd studies of abiogenic magnetite. | 2011 | 21316249 |
| a novel rapid and continuous procedure for large-scale purification of magnetosomes from magnetospirillum gryphiswaldense. | a new rapid and continuous procedure was developed for purifying magnetosomes from magnetospirillum gryphiswaldense msr-1 cells on a large scale. the procedure included these steps: disruption of cells with a high-pressure homogeniser, isolation of magnetosomes with a continuous magnetism isolation system accompanied by low-power ultrasonication and urea treatment, removal of adsorbed and surface proteins with proteinase k, removal of nucleic acids with electro-elution, and replacement of the pb ... | 2011 | 21360144 |
| control generating of bacterial magnetic nanoparticle-doxorubicin conjugates by poly-l-glutamic acid surface modification. | by using poly-l-glutamic acid (plga) to modify the membrane surface of bacterial magnetic nanoparticles (bmps), (bmp)-doxorubicin conjugates (dbmp-p) could be control generated. the doxorubicin loading ratio could be raised up to 81.7% (w/w) in comparison with that of dual functional linkers. dbmp-p was characterized by transmission electron micrographs, attenuated total reflection infrared spectroscopy, magnetic properties, and dynamic light scattering. it is found that increase of the doxorubi ... | 2011 | 21411921 |
| the htra/degp family protease mame is a bifunctional protein with roles in magnetosome protein localization and magnetite biomineralization. | magnetotactic bacteria contain nanometre-sized, membrane-bound organelles, called magnetosomes, which are tasked with the biomineralization of small crystals of the iron oxide magnetite allowing the organism to use geomagnetic field lines for navigation. a key player in this process is the htra/degp family protease mame. in its absence, magnetospirillum magneticum str amb-1 is able to form magnetosome membranes but not magnetite crystals, a defect previously linked to the mislocalization of magn ... | 2011 | 21414040 |
| interruption of the denitrification pathway influences cell growth and magnetosome formation in magnetospirillum magneticum amb-1. | aims: intracellular magnetosome synthesis in magnetotactic bacteria has been proposed to be a process involving functions of a variety of proteins. to learn more about the genetic control that is involved in magnetosome formation, nonmagnetic mutants are screened and characterized. methods and results: conjugation-mediated transposon mutagenesis was applied to screen for nonmagnetic mutants of magnetospirillum magneticum amb-1 that were unable to respond to the magnetic field. a mutant strain ... | 2011 | 21517919 |
| magnetospirillum magneticum amb-1 peroxiredoxins contribute to the aerotolerance and genetic stability of the genomic magnetosome island. | the magnetotactic bacterium magnetospirillum magneticum amb-1 can grow at variable oxygen concentrations, although the intracellular magnetic structures, magnetosomes, are only synthesized under microaerobic or anaerobic conditions. three members of the peroxiredoxin family were identified in m. magneticum amb-1. all purified recombinant proteins displayed thiol-dependent peroxidase activities. allelic replacement mutagenesis revealed that, although the absence of the three peroxidase genes had ... | 2011 | 21535101 |
| self-recognition mechanism of mama, a magnetosome-associated tpr-containing protein, promotes complex assembly. | the magnetosome, a biomineralizing organelle within magnetotactic bacteria, allows their navigation along geomagnetic fields. magnetosomes are membrane-bound compartments containing magnetic nanoparticles and organized into a chain within the cell, the assembly and biomineralization of magnetosomes are controlled by magnetosome-associated proteins. here, we describe the crystal structures of the magnetosome-associated protein, mama, from magnetospirillum magneticum amb-1 and magnetospirillum gry ... | 2011 | 21784982 |
| magnetosome expression of functional camelid antibody fragments (nanobodies) in magnetospirillum gryphiswaldense. | numerous applications of conventional and biogenic magnetic nanoparticles, such as in diagnostics, immunomagnetic separations and magnetic cell labeling, require the immobilization of antibodies. this is usually accomplished by chemical conjugation, which however, has several disadvantages, such as poor efficiency and the need for coupling chemistry. here, we describe a novel strategy to display a functional camelid antibody fragment (nanobody) from an alpaca (lama pacos) on the surface of bacte ... | 2011 | 21764974 |
| single-step production of a recyclable nanobiocatalyst for organophosphate pesticides biodegradation using functionalized bacterial magnetosomes. | enzymes are versatile catalysts in laboratories and on an industrial scale; improving their immobilization would be beneficial to broadening their applicability and ensuring their (re)use. lipid-coated nano-magnets produced by magnetotactic bacteria are suitable for a universally applicable single-step method of enzyme immobilization. by genetically functionalizing the membrane surrounding these magnetite particles with a phosphohydrolase, we engineered an easy-to-purify, robust and recyclable b ... | 2011 | 21738665 |
| frequent mutations within the genomic magnetosome island of magnetospirillum gryphiswaldense are mediated by reca. | genes for magnetosome formation in magnetotactic bacteria are clustered in large genomic magnetosome islands (mai). spontaneous deletions and rearrangements were frequently observed within these regions upon metabolic stress. this instability was speculated to be due to reca-dependent homologous recombination between the numerous sequence repeats present within the mai. here, we show that a reca deficient strain of magnetospirillum gryphiswaldense (strain ik-1) no longer exhibits genetic instabi ... | 2011 | 21821768 |
| semicontinuous culture of magnetospirillum gryphiswaldense msr-1 cells in an autofermentor by nutrient-balanced and isosmotic feeding strategies. | an improved strategy was developed for the high-density culture of magnetospirillum gryphiswaldense strain msr-1 and large-scale magnetosome production in both 7.5- and 42-liter autofermentors. by using a nutrient-balanced feeding strategy and the replacement of carbon and nitrogen sources to reduce accumulation of na(+) and cl(-) ions, we reduced the factors that tend to inhibit cell growth, particularly the increase of osmotic potential. semicontinuous culture was thereby achieved in the autof ... | 2011 | 21724877 |
| snapping magnetosome chains by asymmetric cell division in magnetotactic bacteria. | the mechanism by which prokaryotic cells organize and segregate their intracellular organelles during cell division has recently been the subject of substantial interest. unlike other microorganisms, magnetotactic bacteria (mtb) form internal magnets (known as magnetosome chain) for magnetic orientation, and thus face an additional challenge of dividing and equipartitioning this magnetic receptor to their daughter cells. although mtb have been investigated more than four decades, it is only rece ... | 2011 | 22066928 |
| MamK, a bacterial actin, forms dynamic filaments in vivo that are regulated by the acidic proteins MamJ and LimJ. | Bacterial actins, in contrast to their eukaryotic counterparts, are highly divergent proteins whose wide-ranging functions are thought to correlate with their evolutionary diversity. One clade, represented by the MamK protein of magnetotactic bacteria, is required for the subcellular organization of magnetosomes, membrane-bound organelles that aid in navigation along the earth's magnetic field. Using a fluorescence recovery after photobleaching assay in Magnetospirillum magneticum AMB-1, we find ... | 2011 | 21883528 |
| Magnetosome chains are recruited to cellular division sites and split by asymmetric septation. | Magnetotactic bacteria navigate along magnetic field lines using well-ordered chains of membrane-enclosed magnetic crystals, referred to as magnetosomes, which have emerged as model to investigate organelle biogenesis in prokaryotic systems. To become divided and segregated faithfully during cytokinesis, the magnetosome chain has to be properly positioned, cleaved and separated against intrachain magnetostatic forces. Here we demonstrate that magnetotactic bacteria use dedicated mechanisms to co ... | 2011 | 22026731 |
| anaerobic degradation of 4-methylbenzoate by a new denitrifying bacterium, strain pmbn1. | a novel alphabacterium isolated from freshwater sediments, strain pmbn1, degrading 4-methylbenzoate to co(2) under nitrate-reducing conditions. while strain pmbn1 utilizes several benzoate-derivatives and other polar aromatic compounds, it cannot degrade p-xylene or other hydrocarbons. based on 16s rrna gene sequence analysis, strain pmbn1 affiliates with magnetospirillum. | 2011 | 22179254 |
| magnetospira thiophila, gen. nov. sp. nov., a new marine magnetotactic bacterium that represents a novel lineage within the rhodospirillaceae (alphaproteobacteria). | a marine, magnetotactic bacterium, designated strain mms-1, was isolated from mud and water from a salt marsh in woods hole, massachusetts, after enrichment in defined oxygen concentration/redox gradient medium. mms-1 is an obligate microaerophile capable of chemoorganoheterotrophic and chemolithoautotrophic growth. optimal growth occurred at ph 7.0 and between 24-26 °c. chemolithoautotrophic growth occurs with thiosulfate as the electron donor and autotrophic carbon fixation is via the calvi ... | 2011 | 22140150 |
| The MagA protein of magnetospirilla is not involved in bacterial magnetite biomineralization. | Magnetotactic bacteria have the ability to orient along geomagnetic field lines based on the formation of magnetosomes, which are intracellular nanometer-sized, membrane-enclosed magnetic iron minerals. The formation of these unique bacterial organelles involves several processes like cytoplasmic membrane invagination and magnetosome vesicle formation, accumulation of iron in the vesicles, and crystallization of magnetite. Previous studies suggested that the magA gene may encode a magnetosome-di ... | 2011 | 22194451 |
| structure and molecular evolution of cdgsh iron-sulfur domains. | the recently discovered cdgsh iron-sulfur domains (cisds) are classified into seven major types with a wide distribution throughout the three domains of life. the type 1 protein mitoneet has been shown to fold into a dimer with the signature cdgsh motif binding to a [2fe-2s] cluster. however, the structures of all other types of cisds were unknown. here we report the crystal structures of type 3, 4, and 6 cisds determined at 1.5 å, 1.8 å and 1.15 å resolution, respectively. the type 3 and 4 cisd ... | 2011 | 21949752 |
| intracellular magneto-spatial organization of magnetic organelles inside intact bacterial cells. | magnetotactic bacteria naturally produce magnetosomes, i.e., biological membrane bound nanomagnets, at ambient conditions. it is important to understand simultaneously the possible size variations and the magnetic behavior of nano-magnets inside intact bacterial cells for both applicational purposes as well as to enhance the basic understanding of biomineralization leading to intracellular nano-magnet synthesis. in this work, we utilize high-resolution transmission electron microscopy and near-f ... | 2011 | 21870462 |
| the chemical formula of a magnetotactic bacterium. | elucidation of the chemical logic of life is one of the grand challenges in biology, and essential to the progress of the upcoming field of synthetic biology. treatment of microbial cells explicitly as a "chemical" species in controlled reaction (growth) environments has allowed fascinating discoveries of elemental formulae of a few species that have guided the modern views on compositions of a living cell. application of mass and energy balances on living cells has proved to be useful in modeli ... | 2011 | 22170293 |
| [magnetospirillum aberrantis sp. nov., a new freshwater bacterium with magnetic inclusions]. | | 2011 | 22168012 |
| how iron is transported into magnetosomes. | magnetotactic bacteria are microaerophilic organisms found in sediments or stratified water columns at the oxic-anoxic transition zone or the anoxic regions below. they use magnetite-filled membrane vesicles, magnetosomes, to passively align with, and actively swim along, the geomagnetic field lines in a magneto-aerotactic search for the ideal concentration of molecular oxygen. such an efficient chemotaxis needs magnetosomes that contain nearly perfect magnetite crystals. these magnetosomes orig ... | 2011 | 21999528 |
| The cation diffusion facilitator proteins MamB and MamM of Magnetospirillum gryphiswaldense have distinct and complex functions, and are involved in magnetite biomineralization and magnetosome membrane assembly. | Magnetotactic bacteria form chains of intracellular membrane-enclosed, nanometre-sized magnetite crystals for navigation along the earth's magnetic field. The assembly of these prokaryotic organelles requires several specific polypeptides. Among the most abundant proteins associated with the magnetosome membrane of Magnetospirillum gryphiswaldense are MamB and MamM, which were implicated in magnetosomal iron transport because of their similarity to the cation diffusion facilitator family. Here w ... | 2011 | 22007638 |
| identification of novel mimicry epitopes for cardiac myosin heavy chain-α that induce autoimmune myocarditis in a/j mice. | myocarditis is one cause of sudden cardiac death in young adolescents, and individuals affected with myocarditis can develop dilated cardiomyopathy, a frequent reason for heart transplantation. exposure to environmental microbes has been suspected in the initiation of heart autoimmunity, but the direct causal link is lacking. we report here identification of novel mimicry epitopes that bear sequences similar to those in cardiac myosin heavy chain (myhc)-α 334-352. these epitopes represent bacill ... | 2011 | 21939961 |
| Functional analysis of the magnetosome island in Magnetospirillum gryphiswaldense: the mamAB operon is sufficient for magnetite biomineralization. | Bacterial magnetosomes are membrane-enveloped, nanometer-sized crystals of magnetite, which serve for magnetotactic navigation. All genes implicated in the synthesis of these organelles are located in a conserved genomic magnetosome island (MAI). We performed a comprehensive bioinformatic, proteomic and genetic analysis of the MAI in Magnetospirillum gryphiswaldense. By the construction of large deletion mutants we demonstrate that the entire region is dispensable for growth, and the majority of ... | 2011 | 22043287 |
| magnetosomes on surface: an imaging study approach. | in this study, we deposited isolated magnetosomes from magnetotactic bacteria magnetospirillum strain amb-1 onto solid surfaces using spin coating (sc) and drop coating (dc) techniques. four imaging techniques have been used to visualize the sample structure: scanning and transmission electron microscopy (sem, tem), atomic and magnetic force microscopy (afm, mfm). additionally, dynamic light scattering was applied to measure the hydrodynamic radius of agglomerated/aggregated magnetosomes in a li ... | 2011 | 21953296 |