Differences in Unfolding Energetics of CcdB Toxins From V. fischeri and E. coli

Ccd system is a toxin-antitoxin module (operon) located on plasmids and chromosomes of bacteria. CcdB(F) encoded by ccd operon located on Escherichia coli plasmid F and CcdB(Vfi) encoded by ccd operon located on Vibrio fischeri chromosome are members of the CcdB family of toxins. Native CcdBs are dimers that bind to gyrase-DNA complexes and inhibit DNA transcription and replication. While thermodynamic stability and unfolding characteristics of the plasmidic CcdB(F) in denaturant solutions are reported in detail, the corresponding information on the chromosomal CcdB(Vfi) is rather scarce. Therefore, we studied urea-induced unfolding of CcdB(Vfi) at various temperatures and protein concentrations by circular dichroism spectroscopy. Global model analysis of spectroscopic data suggests that CcdB(Vfi) dimer unfolds to the corresponding monomeric components in a reversible two-state manner. Results reveal that at physiological temperatures CcdB(Vfi) exhibits lower thermodynamic stability compared to CcdB(F). At high urea concentrations CcdB(Vfi), similarly to CcdB(F), retains a significant amount of secondary structure. Differences in thermodynamic parameters of CcdB(Vfi) and CcdB(F) unfolding can reasonably be explained by the differences in their structural features

Production, purification and structural characterisation of recombinant BanLec-Bet v 1

The sublingual route of allergens administration in allergen-specific immunotherapy (ASIT) is proven to be a successful way to treat patients with respiratory allergy. The trend of replacing natural extracts with purified recombinant allergens is growing. Although the purified allergens themselves are not good immunogens, the combined vector systems and adjuvans can improve their immunogenicity 1. Cell surfaces are decorated by different glycan structures, so the lectins specific for these glycans can be used to deliver particular therapeutic to target specific tissue 2. Banana lectin (BanLec) is mannose-specific protein which belongs to the subfamily of Jacalin related lectins 3. Apart from its characteristic to bind glycans, BanLec also modulates immune cells in vitro 4. On the other hand, Bet v 1 (Betula verrucosa) is the major birch pollen allergen. T-cell epitops are distributed over almost entire protein structure 5. In the study the recombinant BanLec-Bet v 1 construct is designed, produced by the recombinant DNA technology, purified and characterized by classical biochemical methods for the application in the ASIT of birch pollen allergy. The expression of newly designed BanLec-Bet v 1 was performed in E. coli BL21 (DE3). After expression the protein was found in the inclusion bodies from which it was extracted with 4 M urea solution. After renaturation, affinity chromatography (Sephadex G-75 superfine) was used for protein purification. Biochemical characterization of the chimera was performed by: SDS PAGE electrophoreses, CD spectroscopy and mass spectrometry. Biological activity of the construct was confirmed by binding of BanLecBet v 1 to a horseradish peroxidase glycoprotein in ELISA. Purified BanLec-Bet v 1 showed molecular mass of 32 kDa. CD spectra of the recombinant construct revealed well defined secondary structures with predominant beta sheets (41.2%). By mass spectrometry 51.8% of the BanLec-Bet v 1 primary structure was confirmed. Biologicaly active recombinant BanLec-Bet v 1 was produced by the recombinant DNA technology. Further in vitro and in vivo studies will evaluate immunomodulatory potential of BanLec-Bet v 1 for application in ASIT

Differences in Unfolding Energetics of CcdB Toxins From V. fischeri and E. coli

Ccd system is a toxin-antitoxin module (operon) located on plasmids and chromosomes of bacteria. CcdB(F) encoded by ccd operon located on Escherichia coli plasmid F and CcdB(Vfi) encoded by ccd operon located on Vibrio fischeri chromosome are members of the CcdB family of toxins. Native CcdBs are dimers that bind to gyrase-DNA complexes and inhibit DNA transcription and replication. While thermodynamic stability and unfolding characteristics of the plasmidic CcdB(F) in denaturant solutions are reported in detail, the corresponding information on the chromosomal CcdB(Vfi) is rather scarce. Therefore, we studied urea-induced unfolding of CcdB(Vfi) at various temperatures and protein concentrations by circular dichroism spectroscopy. Global model analysis of spectroscopic data suggests that CcdB(Vfi) dimer unfolds to the corresponding monomeric components in a reversible two-state manner. Results reveal that at physiological temperatures CcdB(Vfi) exhibits lower thermodynamic stability compared to CcdB(F). At high urea concentrations CcdB(Vfi), similarly to CcdB(F), retains a significant amount of secondary structure. Differences in thermodynamic parameters of CcdB(Vfi) and CcdB(F) unfolding can reasonably be explained by the differences in their structural features

Izostanak planske dokumentacije kao faktor komunalno-higijenskih problema na levoj obali Dunava u gradskom naselju Beograd

Komunalna higijena ima za cilj uspostavljanje sistema upravljanja određenim prostorom i komunalnim delatnostima u funkciji stvaranja kvalitetnijih uslova za život pojedinaca. Ipak, izostanak planiranja komunalnih sadržaja kao posledica izostanka planske dokumentacije dovodi do problema koje je naknadno teško otkloniti (izgradnja kanalizacije, toplovoda, zelenih površina i sl.). Upravo prostor leve obale Dunava u Beogradu (analiziran prostor koji pripada gradskom naselju Beograd) je primer mnogih komunalno-higijenskih problema prouzrokovanih nedostatkom odgovarajuće komunalne infrastrukture, a najveći problemi su nedostatak kanalizacije i sistema za odvođenje viška vode, zatim zagađeni kanali, zagađenje vazduha iz individualnih ložišta, nedostatak zelenih površina, ugrožavanje priobalja (posebno Reva bare, a zatim i budućeg PIO „Forland leve obale Dunava u Beogradu”), problem parkiranja, buke, zagađenja zemljišta i dr. Predmet rada su komunalno-higijenski problemi stambenih kvartova na levoj obali Dunava u gradskom naselju Beograd i analiza uzročnih posledica nedostatka planske dokumentacije. Zadatak je utvrditi mere unapređenja stanja komunalno-higijenskih uslova kroz analizu planske dokumentacije i utvrđivanje trenutnog stanja terenskim istraživanje

Izostanak planske dokumentacije kao faktor komunalno-higijenskih problema na levoj obali Dunava u gradskom naselju Beograd

Komunalna higijena ima za cilj uspostavljanje sistema upravljanja određenim prostorom i komunalnim delatnostima u funkciji stvaranja kvalitetnijih uslova za život pojedinaca. Ipak, izostanak planiranja komunalnih sadržaja kao posledica izostanka planske dokumentacije dovodi do problema koje je naknadno teško otkloniti (izgradnja kanalizacije, toplovoda, zelenih površina i sl.). Upravo prostor leve obale Dunava u Beogradu (analiziran prostor koji pripada gradskom naselju Beograd) je primer mnogih komunalno-higijenskih problema prouzrokovanih nedostatkom odgovarajuće komunalne infrastrukture, a najveći problemi su nedostatak kanalizacije i sistema za odvođenje viška vode, zatim zagađeni kanali, zagađenje vazduha iz individualnih ložišta, nedostatak zelenih površina, ugrožavanje priobalja (posebno Reva bare, a zatim i budućeg PIO „Forland leve obale Dunava u Beogradu”), problem parkiranja, buke, zagađenja zemljišta i dr. Predmet rada su komunalno-higijenski problemi stambenih kvartova na levoj obali Dunava u gradskom naselju Beograd i analiza uzročnih posledica nedostatka planske dokumentacije. Zadatak je utvrditi mere unapređenja stanja komunalno-higijenskih uslova kroz analizu planske dokumentacije i utvrđivanje trenutnog stanja terenskim istraživanje

Challenges in Sustainable Use of Lithium for Highly Innovative Final Products Created and Made in Serbia with EU Environmental Standards

Energy systems of the future should enable transition to clean energy and reduction of CO2 emission. Various options are under consideration and research. One direction of development are photovoltaic, and rechargeable batteries used to store the electricity needed for vehicles and stationary systems (1,2). At the current technological level and market attractiveness among rechargeable batteries significant group are those based on lithium. EU production of raw materials for all batteries is about 1%. Growing demand for lithium are expected in 2050 to be 10-50 times higher than 2018. A lithium deficit in the market is expected (3,4). The companies are searching new locations for lithium mining and production facilities in order to compensate for the deficit. The mineral named Jadarit found in Serbia, contains lithium, sodium, boron and silica. Estimated reserves of Jadarit are of low significance for World production of lithium, but may be significant at EU level and for Serbian economy. Certain companies are interested to enter the production chain from Jadarit. These companies present the possibility for future industrial battery development in Serbia, which may lead innovative final products. They claim optimistic 3-15% increase of GDP (5). Public debate provided argumented shortcomings of currently proposed technology for lithium extraction from Jadarit (6). Major concerns are regarding permanent devastation of lush ecosystem, fertile soil, drinking water, air pollution. These non-monetary assets and their contribution to GDP should be monetized as sine qua non for objective cost-benefit analysis. Therefore, instead of polarization, public debate that identifies key critical points in technology of lithium extraction and its effects on human health and environment provides basis for future research that will develop new technologies capable to protect environment.Conference poster: [https://hdl.handle.net/21.15107/rcub_dais_13015

Challenges in Sustainable Use of Lithium for Highly Innovative Final Products Created and Made in Serbia with EU Environmental Standards

Energy systems of the future should enable transition to clean energy and reduction of CO2 emission. Various options are under consideration and research. One direction of development are photovoltaic, and rechargeable batteries used to store the electricity needed for vehicles and stationary systems (1,2). At the current technological level and market attractiveness among rechargeable batteries significant group are those based on lithium. EU production of raw materials for all batteries is about 1%. Growing demand for lithium are expected in 2050 to be 10-50 times higher than 2018. A lithium deficit in the market is expected (3,4). The companies are searching new locations for lithium mining and production facilities in order to compensate for the deficit.The mineral named Jadarit found in Serbia, contains lithium, sodium, boron and silica. Estimated reserves of Jadarit are of low significance for World production of lithium, but may be significant at EU level and for Serbian economy. Certain companies are interested to enter the production chain from Jadarit. These companies present the possibility for future industrial battery development in Serbia, which may lead innovative final products. They claim optimistic 3-15% increase of GDP (5). Public debate provided argumented shortcomings of currently proposed technology for lithium extraction from Jadarit (6). Major concerns are regarding permanent devastation of lush ecosystem, fertile soil, drinking water, air pollution. These non-monetary assets and their contribution to GDP should be monetized as sine qua non for objective cost-benefit analysis. Therefore, instead of polarization, public debate that identifies key critical points in technology of lithium extraction and its effects on human health and environment provides basis for future research that will develop new technologies capable to protect environment.Conference poster: [https://cer.ihtm.bg.ac.rs/handle/123456789/5498

Foodborne pathogens and their toxins

Foodborne pathogens, mostly bacteria and fungi, but also some viruses, prions and protozoa, contaminate food during production and processing, but also during storage and transport before consuming. During their growth these microorganisms can secrete different components, including toxins, into the extracellular environment. Other harmful substances can be also liberated and can contaminate food after disintegration of food pathogens. Some bacterial and fungal toxins can be resistant to inactivation, and can survive harsh treatment during food processing. Many of these molecules are involved in cellular processes and can indicate different mechanisms of pathogenesis of foodborne organisms. More knowledge about food contaminants can also help understand their inactivation. In the present review the use of proteomics, peptidomics and metabolomics, in addition to other foodomic methods for the detection of foodborne pathogenic fungi and bacteria, is overviewed. Furthermore, it is discussed how these techniques can be used for discovering biomarkers for pathogenicity of foodborne pathogens, determining the mechanisms by which they act, and studying their resistance upon inactivation in food of animal and plant origin. Biological significance Comprehensive and comparative view into the genome and proteome of foodborne pathogens of bacterial or fungal origin and foodomic, mostly proteomic, peptidomic and metabolomic investigation of their toxin production and their mechanism of action is necessary in order to get further information about their virulence, pathogenicity and survival under stress conditions. Furthermore, these data pave the way for identification of biomarkers to trace sources of contamination with food-borne microorganisms and their endo- and exotoxins in order to ensure food safety and prevent the outbreak of food-borne diseases. Therefore, detection of pathogens and their toxins during production, transport and before consume of food produce, as well as protection against food spoilage is a task of great social, economic and public health importance.This is the accepted version of the article: Journal of Proteomics (2016), doi: [https://doi.org/10.1016/j.jprot.2016.04.029