TY  - CONF
AU  - Milošević, Jelica
AU  - Mijin, Nemanja
AU  - Maleš, Luka
AU  - Margetić, Aleksandra
AU  - Jovčić, Branko
AU  - Polović, Natalija
PY  - 2019
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5817
AB  - Proteins are prone to structural changes due to their marginal stability. There are multiple
pathways of structural rearrangements leading to misfolding and aggregation among which
amyloids stand out as highly ordered and remarkably stable forms which appear to be a
global minimum of protein free energy landscape of all proteins. In vitro studies on
different proteins show that destabilizing conditions that favor the state of molten globule
are likely to lead to ordered fibril formation. The presence of various organic and inorganic
molecules was reported to affect amyloid fibril formation, eighter as stimulators or
inhibitors. We investigated the formation of amyloid fibrils of human serum albumin,
ovalbumin and papain in the presence of metal ions, as well as low-molecular-weight
compounds. Proteins were incubated in destabilizing conditions optimized to prolong the
solubility of molten globule state and induce amyloid-like structural changes. The effects
of inorganic and organic additives on fibrillation process were monitored using Thioflavin
T fluorescence, 8-Anilinonaphthalene-1-sulfonic acid fluorescence, Attenuated total
reflection Fourier-transform infrared spectroscopy, electrophoretic and microscopy
techniques. Our results show that the kinetics of amyloid formation is dependent on the
presence of iron, copper, zinc and aluminum salts, as well as different lipophilic lowmolecular-
weight compounds. While some compounds act as complete inhibitors of
fibrillation, others increase the rate of fibrillation process and promote the formation of
mature fibrils.
PB  - University of Belgrade - Falulty of chemistry
PB  - Serbian Biochemical Society
C3  - Proceedings - IX Conference of Serbian Biochemical Society “Diversity in Biochemistry”, 14-16.11.2019. Belgrade, Serbia
T1  - Kinetics of amyloid fibril formation in the presence of metal ions and low-molecular-weight compounds
SP  - 133
UR  - https://hdl.handle.net/21.15107/rcub_cer_5817
ER  - 

@conference{
author = "Milošević, Jelica and Mijin, Nemanja and Maleš, Luka and Margetić, Aleksandra and Jovčić, Branko and Polović, Natalija",
year = "2019",
abstract = "Proteins are prone to structural changes due to their marginal stability. There are multiple
pathways of structural rearrangements leading to misfolding and aggregation among which
amyloids stand out as highly ordered and remarkably stable forms which appear to be a
global minimum of protein free energy landscape of all proteins. In vitro studies on
different proteins show that destabilizing conditions that favor the state of molten globule
are likely to lead to ordered fibril formation. The presence of various organic and inorganic
molecules was reported to affect amyloid fibril formation, eighter as stimulators or
inhibitors. We investigated the formation of amyloid fibrils of human serum albumin,
ovalbumin and papain in the presence of metal ions, as well as low-molecular-weight
compounds. Proteins were incubated in destabilizing conditions optimized to prolong the
solubility of molten globule state and induce amyloid-like structural changes. The effects
of inorganic and organic additives on fibrillation process were monitored using Thioflavin
T fluorescence, 8-Anilinonaphthalene-1-sulfonic acid fluorescence, Attenuated total
reflection Fourier-transform infrared spectroscopy, electrophoretic and microscopy
techniques. Our results show that the kinetics of amyloid formation is dependent on the
presence of iron, copper, zinc and aluminum salts, as well as different lipophilic lowmolecular-
weight compounds. While some compounds act as complete inhibitors of
fibrillation, others increase the rate of fibrillation process and promote the formation of
mature fibrils.",
publisher = "University of Belgrade - Falulty of chemistry, Serbian Biochemical Society",
journal = "Proceedings - IX Conference of Serbian Biochemical Society “Diversity in Biochemistry”, 14-16.11.2019. Belgrade, Serbia",
title = "Kinetics of amyloid fibril formation in the presence of metal ions and low-molecular-weight compounds",
pages = "133",
url = "https://hdl.handle.net/21.15107/rcub_cer_5817"
}

Milošević, J., Mijin, N., Maleš, L., Margetić, A., Jovčić, B.,& Polović, N.. (2019). Kinetics of amyloid fibril formation in the presence of metal ions and low-molecular-weight compounds. in Proceedings - IX Conference of Serbian Biochemical Society “Diversity in Biochemistry”, 14-16.11.2019. Belgrade, Serbia
University of Belgrade - Falulty of chemistry., 133.
https://hdl.handle.net/21.15107/rcub_cer_5817

Milošević J, Mijin N, Maleš L, Margetić A, Jovčić B, Polović N. Kinetics of amyloid fibril formation in the presence of metal ions and low-molecular-weight compounds. in Proceedings - IX Conference of Serbian Biochemical Society “Diversity in Biochemistry”, 14-16.11.2019. Belgrade, Serbia. 2019;:133.
https://hdl.handle.net/21.15107/rcub_cer_5817 .

Milošević, Jelica, Mijin, Nemanja, Maleš, Luka, Margetić, Aleksandra, Jovčić, Branko, Polović, Natalija, "Kinetics of amyloid fibril formation in the presence of metal ions and low-molecular-weight compounds" in Proceedings - IX Conference of Serbian Biochemical Society “Diversity in Biochemistry”, 14-16.11.2019. Belgrade, Serbia (2019):133,
https://hdl.handle.net/21.15107/rcub_cer_5817 .

TY  - JOUR
AU  - Spasojević, Dragica
AU  - Prokopijević, Miloš
AU  - Prodanović, Olivera
AU  - Zelenović, Nevena
AU  - Polović, Natalija
AU  - Radotić, Ksenija
AU  - Prodanović, Radivoje
PY  - 2019
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3028
AB  - Derivatives of xylans were synthesized from corncob xylan by carboxymethylation, oxidization with different molar ratios of periodate (5, 10 15 and 20 mol%) and by reductive amination with tyramine. Modifications of tyramine carboxymethyl xylans (Tyr-CMX) were confirmed by FTIR, UV and NMR spectra. Concentration of ionizable groups increased from 1.5 mmol/g for carboxymethyl xylan (CMX) to 5.4 mmol/g for Tyr-CMX oxidized with 20 mol% of periodate. All Tyr-CMXs were able to form hydrogels the cross-linking reaction with horseradish peroxidase and peroxide. Tyr-CMXs were tested for amyloglucosidase (AG) encapsulation within hydrogel microbeads obtained in a reaction of emulsion polymerization with peroxidase. Average diameter of Tyr-CMX hydrogel microbeads was 52±25 µm and after encapsulation optimization with respect to the extent of CMX modification with tyramine, the concentration of Tyr-CMX, and the amount of added AG, microbeads with AG specific activity of 2 U/mL and 20% yield of immobilization were obtained. The optimum pH of the immobilized AG was not changed compared to the soluble one, while half-life at 60 °C was increased around 10 times. The Michaelis-Menten constant for the immobilized enzyme, 1.03 mM, was significantly lower than that for the soluble one, 1.54 mM. After 5 cycles of repetitive use in batch reactor, the immobilized AG retained 68% of initial activity.
PB  - Springer
T2  - Macromolecular Research
T1  - Peroxidase-Sensitive Tyramine Carboxymethyl Xylan Hydrogels for Enzyme Encapsulation
VL  - 27
IS  - 8
SP  - 764
EP  - 771
DO  - 10.1007/s13233-019-7111-7
ER  - 

@article{
author = "Spasojević, Dragica and Prokopijević, Miloš and Prodanović, Olivera and Zelenović, Nevena and Polović, Natalija and Radotić, Ksenija and Prodanović, Radivoje",
year = "2019",
abstract = "Derivatives of xylans were synthesized from corncob xylan by carboxymethylation, oxidization with different molar ratios of periodate (5, 10 15 and 20 mol%) and by reductive amination with tyramine. Modifications of tyramine carboxymethyl xylans (Tyr-CMX) were confirmed by FTIR, UV and NMR spectra. Concentration of ionizable groups increased from 1.5 mmol/g for carboxymethyl xylan (CMX) to 5.4 mmol/g for Tyr-CMX oxidized with 20 mol% of periodate. All Tyr-CMXs were able to form hydrogels the cross-linking reaction with horseradish peroxidase and peroxide. Tyr-CMXs were tested for amyloglucosidase (AG) encapsulation within hydrogel microbeads obtained in a reaction of emulsion polymerization with peroxidase. Average diameter of Tyr-CMX hydrogel microbeads was 52±25 µm and after encapsulation optimization with respect to the extent of CMX modification with tyramine, the concentration of Tyr-CMX, and the amount of added AG, microbeads with AG specific activity of 2 U/mL and 20% yield of immobilization were obtained. The optimum pH of the immobilized AG was not changed compared to the soluble one, while half-life at 60 °C was increased around 10 times. The Michaelis-Menten constant for the immobilized enzyme, 1.03 mM, was significantly lower than that for the soluble one, 1.54 mM. After 5 cycles of repetitive use in batch reactor, the immobilized AG retained 68% of initial activity.",
publisher = "Springer",
journal = "Macromolecular Research",
title = "Peroxidase-Sensitive Tyramine Carboxymethyl Xylan Hydrogels for Enzyme Encapsulation",
volume = "27",
number = "8",
pages = "764-771",
doi = "10.1007/s13233-019-7111-7"
}

Spasojević, D., Prokopijević, M., Prodanović, O., Zelenović, N., Polović, N., Radotić, K.,& Prodanović, R.. (2019). Peroxidase-Sensitive Tyramine Carboxymethyl Xylan Hydrogels for Enzyme Encapsulation. in Macromolecular Research
Springer., 27(8), 764-771.
https://doi.org/10.1007/s13233-019-7111-7

Spasojević D, Prokopijević M, Prodanović O, Zelenović N, Polović N, Radotić K, Prodanović R. Peroxidase-Sensitive Tyramine Carboxymethyl Xylan Hydrogels for Enzyme Encapsulation. in Macromolecular Research. 2019;27(8):764-771.
doi:10.1007/s13233-019-7111-7 .

Spasojević, Dragica, Prokopijević, Miloš, Prodanović, Olivera, Zelenović, Nevena, Polović, Natalija, Radotić, Ksenija, Prodanović, Radivoje, "Peroxidase-Sensitive Tyramine Carboxymethyl Xylan Hydrogels for Enzyme Encapsulation" in Macromolecular Research, 27, no. 8 (2019):764-771,
https://doi.org/10.1007/s13233-019-7111-7 . .

TY  - CONF
AU  - Marković, Olivera
AU  - Konstantinović, Jelena M.
AU  - Cvijetić, Ilija
AU  - Amézqueta, Susana
AU  - Valko, Klara
AU  - Ràfols, Clara
AU  - Polović, Natalija
AU  - Šolaja, Bogdan
AU  - Verbić, Tatjana
PY  - 2017
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3403
AB  - Drug molecules in vivo may be bound to proteins and lipids in plasma and/or in tissues, or free (unbound) in diffusion among the aqueous environment of the blood and tissues. Data from in vitro plasma protein binding experiments that determine the fraction of protein-bound drug are  frequently used in drug discovery. Methods used for drug –  plasma protein binding (PPB) studies are numerous and can be divided into two main groups: separation methods (enabling the calculation of binding parameters, i.e. the number of binding sites and their respective affinity constants) and non-separation methods (describing predominantly qualitative parameters of the ligand-protein complex).
PB  - International Association of Physical Chemists
C3  - 6th World Conference on Physico-Chemical Methods in Drug Discovery, Zagreb, Croatia, September 4-7, 2017 - Book of Abstracts
T1  - Measurements of plasma protein binding – variety of experimental techniques
SP  - 30
EP  - 30
UR  - https://hdl.handle.net/21.15107/rcub_cer_3403
ER  - 

@conference{
author = "Marković, Olivera and Konstantinović, Jelena M. and Cvijetić, Ilija and Amézqueta, Susana and Valko, Klara and Ràfols, Clara and Polović, Natalija and Šolaja, Bogdan and Verbić, Tatjana",
year = "2017",
abstract = "Drug molecules in vivo may be bound to proteins and lipids in plasma and/or in tissues, or free (unbound) in diffusion among the aqueous environment of the blood and tissues. Data from in vitro plasma protein binding experiments that determine the fraction of protein-bound drug are  frequently used in drug discovery. Methods used for drug –  plasma protein binding (PPB) studies are numerous and can be divided into two main groups: separation methods (enabling the calculation of binding parameters, i.e. the number of binding sites and their respective affinity constants) and non-separation methods (describing predominantly qualitative parameters of the ligand-protein complex).",
publisher = "International Association of Physical Chemists",
journal = "6th World Conference on Physico-Chemical Methods in Drug Discovery, Zagreb, Croatia, September 4-7, 2017 - Book of Abstracts",
title = "Measurements of plasma protein binding – variety of experimental techniques",
pages = "30-30",
url = "https://hdl.handle.net/21.15107/rcub_cer_3403"
}

Marković, O., Konstantinović, J. M., Cvijetić, I., Amézqueta, S., Valko, K., Ràfols, C., Polović, N., Šolaja, B.,& Verbić, T.. (2017). Measurements of plasma protein binding – variety of experimental techniques. in 6th World Conference on Physico-Chemical Methods in Drug Discovery, Zagreb, Croatia, September 4-7, 2017 - Book of Abstracts
International Association of Physical Chemists., 30-30.
https://hdl.handle.net/21.15107/rcub_cer_3403

Marković O, Konstantinović JM, Cvijetić I, Amézqueta S, Valko K, Ràfols C, Polović N, Šolaja B, Verbić T. Measurements of plasma protein binding – variety of experimental techniques. in 6th World Conference on Physico-Chemical Methods in Drug Discovery, Zagreb, Croatia, September 4-7, 2017 - Book of Abstracts. 2017;:30-30.
https://hdl.handle.net/21.15107/rcub_cer_3403 .

Marković, Olivera, Konstantinović, Jelena M., Cvijetić, Ilija, Amézqueta, Susana, Valko, Klara, Ràfols, Clara, Polović, Natalija, Šolaja, Bogdan, Verbić, Tatjana, "Measurements of plasma protein binding – variety of experimental techniques" in 6th World Conference on Physico-Chemical Methods in Drug Discovery, Zagreb, Croatia, September 4-7, 2017 - Book of Abstracts (2017):30-30,
https://hdl.handle.net/21.15107/rcub_cer_3403 .

TY  - JOUR
AU  - Prokopovic, Vladimir
AU  - Popović, Milica
AU  - Anđelković, Uroš
AU  - Marsavelski, Aleksandra
AU  - Raskovic, Brankica
AU  - Gavrović-Jankulović, Marija
AU  - Polović, Natalija
PY  - 2014
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/1508
AB  - Objective: Human BPIFA2 (parotid secretory protein) is a ubiquitous soluble salivary protein, which belongs to the PLUNC family of proteins. Having sequence similarity to bactericidal/permeability-increasing protein and lipopolysaccharide-binding protein, PLUNC proteins are probably involved in local antibacterial response at mucosal sites, such as oral cavity. The aim of the study was to isolate and characterize human BPIFA2. Design: In this paper, we report one-step affinity chromatography method for BPIFA2 purification from whole human saliva. The isolated BPIFA2 was identified by trypsin mass fingerprinting and characterized by electrophoretic methods. Antibacterial activity of BPIFA2 against model microorganism Pseudomonas aeruginosa was shown in minimum inhibitory concentration and time kill study assays. Results: The protein showed microheterogeneity, both in molecular weight and pI value. BPIFA2 inhibited the growth of P. aeruginosa in microgram concentration range determined by minimum inhibitory concentration assay. In the time kill study, 32 mu g/mL BPIFA2 showed clear bactericidal activity and did not cause any aggregation of bacteria. Conclusion: Affinity chromatography is well suited for isolation of functional BPIFA2 with a potent bactericidal activity against P. aeruginosa.
PB  - Oxford : Pergamon-Elsevier Science Ltd
T2  - Archives of Oral Biology
T1  - Isolation, biochemical characterization and anti-bacterial activity of BPIFA2 protein
VL  - 59
IS  - 3
SP  - 302
EP  - 309
DO  - 10.1016/j.archoralbio.2013.12.005
ER  - 

@article{
author = "Prokopovic, Vladimir and Popović, Milica and Anđelković, Uroš and Marsavelski, Aleksandra and Raskovic, Brankica and Gavrović-Jankulović, Marija and Polović, Natalija",
year = "2014",
abstract = "Objective: Human BPIFA2 (parotid secretory protein) is a ubiquitous soluble salivary protein, which belongs to the PLUNC family of proteins. Having sequence similarity to bactericidal/permeability-increasing protein and lipopolysaccharide-binding protein, PLUNC proteins are probably involved in local antibacterial response at mucosal sites, such as oral cavity. The aim of the study was to isolate and characterize human BPIFA2. Design: In this paper, we report one-step affinity chromatography method for BPIFA2 purification from whole human saliva. The isolated BPIFA2 was identified by trypsin mass fingerprinting and characterized by electrophoretic methods. Antibacterial activity of BPIFA2 against model microorganism Pseudomonas aeruginosa was shown in minimum inhibitory concentration and time kill study assays. Results: The protein showed microheterogeneity, both in molecular weight and pI value. BPIFA2 inhibited the growth of P. aeruginosa in microgram concentration range determined by minimum inhibitory concentration assay. In the time kill study, 32 mu g/mL BPIFA2 showed clear bactericidal activity and did not cause any aggregation of bacteria. Conclusion: Affinity chromatography is well suited for isolation of functional BPIFA2 with a potent bactericidal activity against P. aeruginosa.",
publisher = "Oxford : Pergamon-Elsevier Science Ltd",
journal = "Archives of Oral Biology",
title = "Isolation, biochemical characterization and anti-bacterial activity of BPIFA2 protein",
volume = "59",
number = "3",
pages = "302-309",
doi = "10.1016/j.archoralbio.2013.12.005"
}

Prokopovic, V., Popović, M., Anđelković, U., Marsavelski, A., Raskovic, B., Gavrović-Jankulović, M.,& Polović, N.. (2014). Isolation, biochemical characterization and anti-bacterial activity of BPIFA2 protein. in Archives of Oral Biology
Oxford : Pergamon-Elsevier Science Ltd., 59(3), 302-309.
https://doi.org/10.1016/j.archoralbio.2013.12.005

Prokopovic V, Popović M, Anđelković U, Marsavelski A, Raskovic B, Gavrović-Jankulović M, Polović N. Isolation, biochemical characterization and anti-bacterial activity of BPIFA2 protein. in Archives of Oral Biology. 2014;59(3):302-309.
doi:10.1016/j.archoralbio.2013.12.005 .

Prokopovic, Vladimir, Popović, Milica, Anđelković, Uroš, Marsavelski, Aleksandra, Raskovic, Brankica, Gavrović-Jankulović, Marija, Polović, Natalija, "Isolation, biochemical characterization and anti-bacterial activity of BPIFA2 protein" in Archives of Oral Biology, 59, no. 3 (2014):302-309,
https://doi.org/10.1016/j.archoralbio.2013.12.005 . .

TY  - JOUR
AU  - Stanić, Dragana
AU  - Radosavljevic, J.
AU  - Polović, Natalija
AU  - Jadranin, Milka
AU  - Popović, M.
AU  - Vuckovic, O.
AU  - Burazer, L.
AU  - Jankov, R.
AU  - Ćirković Veličković, Tanja
PY  - 2009
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/608
AB  - The use of enzymes may improve the functional properties of various food ingredients. The aim of this study was to examine the effects of proteolytic contaminants in phenol oxidases on β-lactoglobulin (BLG). In the presence of Trametes versicolor laccase and Agaricus bisporus tyrosinase, both variants of BLG (A and B) underwent removal of a peptide from the N-terminus. The truncated forms were more susceptible to digestion by pepsin. The truncation of BLG resulted from contaminating proteases and not due to the action of phenol oxidases. The removal of N-terminal peptides proceeded quickly, while the rest of the globular protein remained resistant to proteolysis for up to 3 h. In the case of the application of enzymes in food bioprocessing, it may be important to carefully monitor the effects of contaminating proteases in enzyme preparations used.
T2  - International Dairy Journal
T1  - Removal of N-terminal peptides from β-lactoglobulin by proteolytic contaminants in a commercial phenol oxidase preparation
VL  - 19
IS  - 12
SP  - 746
EP  - 752
DO  - 10.1016/j.idairyj.2009.05.008
ER  - 

@article{
author = "Stanić, Dragana and Radosavljevic, J. and Polović, Natalija and Jadranin, Milka and Popović, M. and Vuckovic, O. and Burazer, L. and Jankov, R. and Ćirković Veličković, Tanja",
year = "2009",
abstract = "The use of enzymes may improve the functional properties of various food ingredients. The aim of this study was to examine the effects of proteolytic contaminants in phenol oxidases on β-lactoglobulin (BLG). In the presence of Trametes versicolor laccase and Agaricus bisporus tyrosinase, both variants of BLG (A and B) underwent removal of a peptide from the N-terminus. The truncated forms were more susceptible to digestion by pepsin. The truncation of BLG resulted from contaminating proteases and not due to the action of phenol oxidases. The removal of N-terminal peptides proceeded quickly, while the rest of the globular protein remained resistant to proteolysis for up to 3 h. In the case of the application of enzymes in food bioprocessing, it may be important to carefully monitor the effects of contaminating proteases in enzyme preparations used.",
journal = "International Dairy Journal",
title = "Removal of N-terminal peptides from β-lactoglobulin by proteolytic contaminants in a commercial phenol oxidase preparation",
volume = "19",
number = "12",
pages = "746-752",
doi = "10.1016/j.idairyj.2009.05.008"
}

Stanić, D., Radosavljevic, J., Polović, N., Jadranin, M., Popović, M., Vuckovic, O., Burazer, L., Jankov, R.,& Ćirković Veličković, T.. (2009). Removal of N-terminal peptides from β-lactoglobulin by proteolytic contaminants in a commercial phenol oxidase preparation. in International Dairy Journal, 19(12), 746-752.
https://doi.org/10.1016/j.idairyj.2009.05.008

Stanić D, Radosavljevic J, Polović N, Jadranin M, Popović M, Vuckovic O, Burazer L, Jankov R, Ćirković Veličković T. Removal of N-terminal peptides from β-lactoglobulin by proteolytic contaminants in a commercial phenol oxidase preparation. in International Dairy Journal. 2009;19(12):746-752.
doi:10.1016/j.idairyj.2009.05.008 .

Stanić, Dragana, Radosavljevic, J., Polović, Natalija, Jadranin, Milka, Popović, M., Vuckovic, O., Burazer, L., Jankov, R., Ćirković Veličković, Tanja, "Removal of N-terminal peptides from β-lactoglobulin by proteolytic contaminants in a commercial phenol oxidase preparation" in International Dairy Journal, 19, no. 12 (2009):746-752,
https://doi.org/10.1016/j.idairyj.2009.05.008 . .