TY  - JOUR
AU  - Pasti, Tamara Lazarevic
AU  - Momic, Tatjana
AU  - Onjia, Antonije E.
AU  - Vujisić, Ljubodrag V.
AU  - Vasic, Vesna
PY  - 2010
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/1106
AB  - In order to improve the sensitivity of assays for inhibitors of the enzyme acetylcholine esterase (AChE), an effective method was developed for the conversion of the organophosphate pesticides (OPs) diazinon, malathion, chlorpyrifos, azinphos-methyl and phorate into more toxic inhibitors. This was accomplished by converting them from the thio form into their oxo form using the enzyme myeloperoxidase. The oxo forms, which are the only products of conversion, were determined by AChE bioassays, using either the free enzyme, or a flow injection analysis manifold with immobilized AChE and spectrophotometric detection. All modified OPs exhibited inhibitory power at ppb levels and within 10 min. The method is considered to represent an excellent means for improving the sensitivity of assays for determination of OPs.
PB  - Springer Wien, Wien
T2  - Microchimica Acta
T1  - Myeloperoxidase-mediated oxidation of organophosphorus pesticides as a pre-step in their determination by AChE based bioanalytical methods
VL  - 170
IS  - 3-4
SP  - 289
EP  - 297
DO  - 10.1007/s00604-010-0324-2
ER  - 

@article{
author = "Pasti, Tamara Lazarevic and Momic, Tatjana and Onjia, Antonije E. and Vujisić, Ljubodrag V. and Vasic, Vesna",
year = "2010",
abstract = "In order to improve the sensitivity of assays for inhibitors of the enzyme acetylcholine esterase (AChE), an effective method was developed for the conversion of the organophosphate pesticides (OPs) diazinon, malathion, chlorpyrifos, azinphos-methyl and phorate into more toxic inhibitors. This was accomplished by converting them from the thio form into their oxo form using the enzyme myeloperoxidase. The oxo forms, which are the only products of conversion, were determined by AChE bioassays, using either the free enzyme, or a flow injection analysis manifold with immobilized AChE and spectrophotometric detection. All modified OPs exhibited inhibitory power at ppb levels and within 10 min. The method is considered to represent an excellent means for improving the sensitivity of assays for determination of OPs.",
publisher = "Springer Wien, Wien",
journal = "Microchimica Acta",
title = "Myeloperoxidase-mediated oxidation of organophosphorus pesticides as a pre-step in their determination by AChE based bioanalytical methods",
volume = "170",
number = "3-4",
pages = "289-297",
doi = "10.1007/s00604-010-0324-2"
}

Pasti, T. L., Momic, T., Onjia, A. E., Vujisić, L. V.,& Vasic, V.. (2010). Myeloperoxidase-mediated oxidation of organophosphorus pesticides as a pre-step in their determination by AChE based bioanalytical methods. in Microchimica Acta
Springer Wien, Wien., 170(3-4), 289-297.
https://doi.org/10.1007/s00604-010-0324-2

Pasti TL, Momic T, Onjia AE, Vujisić LV, Vasic V. Myeloperoxidase-mediated oxidation of organophosphorus pesticides as a pre-step in their determination by AChE based bioanalytical methods. in Microchimica Acta. 2010;170(3-4):289-297.
doi:10.1007/s00604-010-0324-2 .

Pasti, Tamara Lazarevic, Momic, Tatjana, Onjia, Antonije E., Vujisić, Ljubodrag V., Vasic, Vesna, "Myeloperoxidase-mediated oxidation of organophosphorus pesticides as a pre-step in their determination by AChE based bioanalytical methods" in Microchimica Acta, 170, no. 3-4 (2010):289-297,
https://doi.org/10.1007/s00604-010-0324-2 . .

TY  - JOUR
AU  - Momic, Tatjana
AU  - Vujčić, Zoran
AU  - Vasic, Vesna
PY  - 2008
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/946
AB  - The inhibition of myeloperoxidase (MPO), isolated from human neutrophils, by quercetin was investigated by following peroxidase activity of the enzyme using o-dianisidine as the substrate. The inhibition parameters (IC(50)) were obtained by graphical analysis of the inhibition curves. A reaction mechanism, which involved the enzyme inhibition by quercetin and H(2)O(2) in excess, was proposed. The rate and equilibrium constants for the proposed reaction path were calculated from experimental data. Kinetic analysis in noninhibiting H(2)O(2) concentration range in the absence and the presence of quercetin revealed that the reaction mechanism underwent Michaelis-Menten kinetics. K(m)(app,H2O2) and V(max)(app) values indicated that quercetin was a mixed inhibitor of MPO activity. The initial reaction rates were recalculated using the obtained results. Calculated curves fitted the experimental results within the range of experimental error. (C) 2008 Wiley Periodicals, Inc.
PB  - Wiley-Blackwell, Malden
T2  - International Journal of Chemical Kinetics
T1  - Kinetics of inhibition of peroxidase activity of myeloperoxidase by quercetin
VL  - 40
IS  - 7
SP  - 384
EP  - 394
DO  - 10.1002/kin.20319
ER  - 

@article{
author = "Momic, Tatjana and Vujčić, Zoran and Vasic, Vesna",
year = "2008",
abstract = "The inhibition of myeloperoxidase (MPO), isolated from human neutrophils, by quercetin was investigated by following peroxidase activity of the enzyme using o-dianisidine as the substrate. The inhibition parameters (IC(50)) were obtained by graphical analysis of the inhibition curves. A reaction mechanism, which involved the enzyme inhibition by quercetin and H(2)O(2) in excess, was proposed. The rate and equilibrium constants for the proposed reaction path were calculated from experimental data. Kinetic analysis in noninhibiting H(2)O(2) concentration range in the absence and the presence of quercetin revealed that the reaction mechanism underwent Michaelis-Menten kinetics. K(m)(app,H2O2) and V(max)(app) values indicated that quercetin was a mixed inhibitor of MPO activity. The initial reaction rates were recalculated using the obtained results. Calculated curves fitted the experimental results within the range of experimental error. (C) 2008 Wiley Periodicals, Inc.",
publisher = "Wiley-Blackwell, Malden",
journal = "International Journal of Chemical Kinetics",
title = "Kinetics of inhibition of peroxidase activity of myeloperoxidase by quercetin",
volume = "40",
number = "7",
pages = "384-394",
doi = "10.1002/kin.20319"
}

Momic, T., Vujčić, Z.,& Vasic, V.. (2008). Kinetics of inhibition of peroxidase activity of myeloperoxidase by quercetin. in International Journal of Chemical Kinetics
Wiley-Blackwell, Malden., 40(7), 384-394.
https://doi.org/10.1002/kin.20319

Momic T, Vujčić Z, Vasic V. Kinetics of inhibition of peroxidase activity of myeloperoxidase by quercetin. in International Journal of Chemical Kinetics. 2008;40(7):384-394.
doi:10.1002/kin.20319 .

Momic, Tatjana, Vujčić, Zoran, Vasic, Vesna, "Kinetics of inhibition of peroxidase activity of myeloperoxidase by quercetin" in International Journal of Chemical Kinetics, 40, no. 7 (2008):384-394,
https://doi.org/10.1002/kin.20319 . .

TY  - JOUR
AU  - Momic, T
AU  - Vujčić, Zoran
AU  - Vasic, V
AU  - Horvat, A
PY  - 2002
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/530
AB  - 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.
AB  - 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.
PB  - Serbian Chemical Soc, Belgrade
T2  - Journal of the Serbian Chemical Society
T1  - Immobilization of Na,K-ATPase isolated from rat brain synaptic plasma membranes
T1  - Imobilizacija Na,K-ATPpaze izolovane iz sinaptičkih plazma-membrana mozga pacova
VL  - 67
IS  - 12
SP  - 809
EP  - 817
DO  - 10.2298/JSC0212809M
ER  - 

@article{
author = "Momic, T and Vujčić, Zoran and Vasic, V and Horvat, A",
year = "2002",
abstract = "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.",
publisher = "Serbian Chemical Soc, Belgrade",
journal = "Journal of the Serbian Chemical Society",
title = "Immobilization of Na,K-ATPase isolated from rat brain synaptic plasma membranes, Imobilizacija Na,K-ATPpaze izolovane iz sinaptičkih plazma-membrana mozga pacova",
volume = "67",
number = "12",
pages = "809-817",
doi = "10.2298/JSC0212809M"
}

Momic, T., Vujčić, Z., Vasic, V.,& Horvat, A.. (2002). Immobilization of Na,K-ATPase isolated from rat brain synaptic plasma membranes. in Journal of the Serbian Chemical Society
Serbian Chemical Soc, Belgrade., 67(12), 809-817.
https://doi.org/10.2298/JSC0212809M

Momic T, Vujčić Z, Vasic V, Horvat A. Immobilization of Na,K-ATPase isolated from rat brain synaptic plasma membranes. in Journal of the Serbian Chemical Society. 2002;67(12):809-817.
doi:10.2298/JSC0212809M .

Momic, T, Vujčić, Zoran, Vasic, V, Horvat, A, "Immobilization of Na,K-ATPase isolated from rat brain synaptic plasma membranes" in Journal of the Serbian Chemical Society, 67, no. 12 (2002):809-817,
https://doi.org/10.2298/JSC0212809M . .