38 research outputs found

    Imobilizacija Na,K-ATPpaze izolovane iz sinaptičkih plazma-membrana mozga pacova

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    Rat brain Na,K-ATPase partially purified by SDS from synaptic plasma membranes (SPM) was immobilized by adsorption on nitrocellulose (NC), polyvinylidene fluoride (PVDF) and glass fiber (GF) membranes, Partial SDS solubilization increased the enzyme activity by 40%. With regard to the presentation of the enzyme activity. nitrocellulose Was shown to be the optimal support for die immobilization, The enzyme showed the highest percentage activity (14%) after 30 min of SPM adsorption. at 20 degreesC under the vaccum. with 25 mug of proteins per NC disc filter. In addition, adsorption on NC stabilizes the Na,K-ATPase, since the activity was substantial 72 h after adsorption at 20 degreesC, After adsorption. the sensitivity of the enzyme to HgCl2 and CdCl2 inhibition was higher, The results show that immobilized Na,K-NTPase SPM can be used as a practical model for the detection of metal ions in different samples.Delimično prečišćena Na,K-ATPaza sinaptičkih plazma–membrana (SPM) mozga pacova imobilizovana je adsorpcijom na nitrocelulozne (NC) poliviniliden-fluorid (PVDF) membrane i membrane od staklenih vlakana (SV). Aktivnost enzima delimično prečišćenog solubilizacijom SDS-om povećana je oko 40%. Najveći procenat aktivnosti (14%) enzim zadržava posle 30 minuta adsorpcije SPM na 20ºC, pod vakuumom, sa 25 μg proteina po nitroceluloznom disku. Na,K-ATPaza imobilizovana na nitroceluloznoj membrani stabilna je 72 sata na 20ºC. Adsorpcijom, osetljivost enzima na inhibiciju Hg2+ i Cd2+ se povećava. Rezultati pokazuju da se imobilizovana Na,K-ATPaza SPM može koristiti za detekciju toksičnih metalnih jona u različitim uzorcima

    On some interconnections between combinatorial optimization and extremal graph theory

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    The uniting feature of combinatorial optimization and extremal graph theory is that in both areas one should find extrema of a function defined in most cases on a finite set. While in combinatorial optimization the point is in developing efficient algorithms and heuristics for solving specified types of problems, the extremal graph theory deals with finding bounds for various graph invariants under some constraints and with constructing extremal graphs. We analyze by examples some interconnections and interactions of the two theories and propose some conclusions

    Novel 1,3,4-thiadiazole-chalcone hybrids containing catechol moiety: synthesis, antioxidant activity, cytotoxicity and DNA interaction studies

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    Hybrid compounds that combine the 1,3,4-thiadiazole-containing catechol moiety with a chalcone motif were synthesized and examined for their antioxidant activity, cytotoxicity, and DNA-binding activity. A series of thirteen compounds showed strong antioxidant and cytotoxic effects on human acute promyelocytic leukemia HL-60 cells. Several compounds exerted good cytotoxic activities on cervical adenocarcinoma HeLa cells. The treatment of HeLa cells with IC50 and double IC50 concentrations of the compounds 5a, 5c, 5f, and 5m induced a statistically significant increase in the percentage of cells within a subG1 cell cycle phase. The examined compounds caused G2/M cell cycle arrest in HeLa cells. Each of these compounds triggered apoptosis in HeLa cells through activation of caspase-3, the main effector caspase, caspase-8, which is involved in the extrinsic apoptotic pathway, and caspase-9, which is involved in the intrinsic apoptotic pathway. All of the examined compounds decreased the expression levels of MMP2 in HeLa cells and levels of protumorigenic miR-133b. Compounds 5a and 5m lowered the expression level of oncogenic miR-21 in HeLa cells. In addition, compounds 5a, 5f, and 5m decreased the expression levels of oncogenic miR-155 while the treatment of HeLa cells with compounds 5a, 5c, and 5f increased expression of tumor-suppressive miR-206. Observed effects of these compounds on expression levels of four examined miRNAs suggest their prominent cancer-suppressive activity. An investigation by absorption and fluorescence spectroscopy showed more efficient calf thymus DNA binding activity of the compound 5m in comparison to other tested compounds. Results of a pUC19 plasmid cleavage study and comet assay showed DNA damaging activities of compounds 5a and 5c.Related to published version:[https://imagine.imgge.bg.ac.rs/handle/123456789/1168]This is the peer reviewed version of the paper: Jakovljević, K., Joksović, M. D., Matić, I., Petrović, N., Stanojković, T., Sladić, D., Vujčić, M., Janović, B., Joksović, L., Trifunović, S., & Marković, V. (2018). Novel 1,3,4-thiadiazole-chalcone hybrids containing catechol moiety: Synthesis, antioxidant activity, cytotoxicity and DNA interaction studies. Medchemcomm, 9(10), 1679–1697. [https://doi.org/10.1039/c8md00316e

    Screening of pectinase-producing Aspergillus spp. for use in strawberry juice clarification

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    U ovom radu urađen je skrining sojeva Aspergillus spp. koji proizvode pektinaze fermentacijom u tečnom medijumu, a koje su efikasne u izbistravanju soka od jagode. Endo-pektinaze su detektovane difuzionim testom, a ukupna pektinazna aktivnost određena je DNS metodom. Izbistravanje soka nakon tretmana pektinazama određeno je merenjem transmitancije na 660 nm, a povećanje prinosa soka izmereno je centrifugiranjem. Dobijeni rezultati su pokazali da su ove pektinaze visokoefikasne za tretman soka od jagode u poređenju sa komercijalnim pektinaznim preparatom Lafase Fruit.In this work, the screening of Aspergillus spp which produce pectinases by fermentation in a liquid medium was performed, as pectinases are effective in clarifying strawberry juice. Endo-pectinases were detected by the diffusion assay, and total pectinase activity was determined by the DNS method. The clarification of juice after pectinase treatment was determined by measuring the transmission at 660 nm, and an increase in juice yield was measured by centrifugation. The results obtained showed that these pectinases are very effective for the treatment of strawberry juice in comparison with the commercial pectinase preparation Lafase Fruit.59th Meeting of the Serbian Chemical Society; June 1-2, 2023, Novi Sad, Serbi

    Interactions of cytotoxic amino acid derivatives of tert-butylquinone with DNA and lysozyme

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    The interactions of nine amino acid derivatives of tert-butylquinone with biomacromolecules were studied. Sodium dodecyl sulphate (SDS) gel electrophoresis and mass spectrometry confirmed the absence of modifications of lysozyme by any of the synthesized compounds. Spectrophotometric studies demonstrated hyperchromism, i.e., the existence of interactions between the quinones and calf thymus DNA (CT-DNA). Determination of the binding constants by absorption titration indicated weak interactions between the quinone derivatives and CT-DNA. The quenching of fluorescence of the intercalator ethidium bromide (EB) from the EB-CT-DNA system and of the minor groove binder Hoechst 33258 (H) from the H-CT-DNA system by the synthesized derivatives indicated interactions of the compounds and CT-DNA. Circular dichroism (CD) spectra demonstrated a non-intercalative binding mode of the quinone derivatives to CT-DNA. Molecular docking results confirmed binding to the minor groove. The electrophoretic pattern showed no cleavage of the pUC19 plasmid in the presence of any of the synthesized compounds. The ability of the derivatives to scavenge radicals was confirmed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test. All the presented results suggest that the DNA minor groove binding is the principal mechanism of action of the examined amino acid derivatives

    A decade with vamdc: Results and ambitions

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    This paper presents an overview of the current status of the Virtual Atomic and Molecular Data Centre (VAMDC) e-infrastructure, including the current status of the VAMDC-connected (or to be connected) databases, updates on the latest technological development within the infrastructure and a presentation of some application tools that make use of the VAMDC e-infrastructure. We analyse the past 10 years of VAMDC development and operation, and assess their impact both on the field of atomic and molecular (A&amp;M) physics itself and on heterogeneous data management in international cooperation. The highly sophisticated VAMDC infrastructure and the related databases developed over this long term make them a perfect resource of sustainable data for future applications in many fields of research. However, we also discuss the current limitations that prevent VAMDC from becoming the main publishing platform and the main source of A&amp;M data for user communities, and present possible solutions under investigation by the consortium. Several user application examples are presented, illustrating the benefits of VAMDC in current research applications, which often need the A&amp;M data from more than one database. Finally, we present our vision for the future of VAMDC.</jats:p

    A Decade with VAMDC: Results and Ambitions

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    This paper presents an overview of the current status of the Virtual Atomic and Molecular Data Centre (VAMDC) e-infrastructure, including the current status of the VAMDC-connected (or to be connected) databases, updates on the latest technological development within the infrastructure and a presentation of some application tools that make use of the VAMDC e-infrastructure. We analyse the past 10 years of VAMDC development and operation, and assess their impact both on the field of atomic and molecular (A&M) physics itself and on heterogeneous data management in international cooperation. The highly sophisticated VAMDC infrastructure and the related databases developed over this long term make them a perfect resource of sustainable data for future applications in many fields of research. However, we also discuss the current limitations that prevent VAMDC from becoming the main publishing platform and the main source of A&M data for user communities, and present possible solutions under investigation by the consortium. Several user application examples are presented, illustrating the benefits of VAMDC in current research applications, which often need the A&M data from more than one database. Finally, we present our vision for the future of VAMDC
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