TY  - JOUR
AU  - Laketa, Danijela
AU  - Bogdanović Pristov, Jelena
AU  - Prodanović, Radivoje
AU  - Kalauzi, Aleksandar
AU  - Radotić, Ksenija
PY  - 2010
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/415
AB  - We studied the dependence of peroxidase (POD) activity on pH in crude extract of Picea omorika (Pane.) Purkinye needles and in its acidic and basic fractions, obtained by ion exchange chromatography. Nonlinear regression was applied on the activity data with pH as the explaining variable, using the Levenberg-Marquardt algorithm. Studying crude extract at three different temperatures, the shape of the simulated activity/pH dependences indicated an existence of two components, which was confirmed by mathematical modeling. The kinetic parameters Act(0) K-EH and K-EOH of both components are presented. The curves and pH optima shifted under increasing temperatures towards lower pH values, which was verified after decomposition. Nonlinear regression detected the presence of two components for both fractions, and there is no considerable difference between their pH optima. Our results show for the first time that the sum of components, each described by the mathematical model employed, can be used to explain the complex pH-related POD activity in the extract with two or more enzyme forms simultaneously active.
PB  - General Physiol And Biophysics, Bratislava
T2  - General Physiology and Biophysics
T1  - The effect of pH on the activity of soluble peroxidase in needles of Serbian spruce (Picea omorika (Panc.) Purkinye): application of a mathematical model
EP  - 128
IS  - 2
SP  - 122
VL  - 29
DO  - 10.4149/gpb_2010_02_122
ER  - 

@article{
author = "Laketa, Danijela and Bogdanović Pristov, Jelena and Prodanović, Radivoje and Kalauzi, Aleksandar and Radotić, Ksenija",
year = "2010",
abstract = "We studied the dependence of peroxidase (POD) activity on pH in crude extract of Picea omorika (Pane.) Purkinye needles and in its acidic and basic fractions, obtained by ion exchange chromatography. Nonlinear regression was applied on the activity data with pH as the explaining variable, using the Levenberg-Marquardt algorithm. Studying crude extract at three different temperatures, the shape of the simulated activity/pH dependences indicated an existence of two components, which was confirmed by mathematical modeling. The kinetic parameters Act(0) K-EH and K-EOH of both components are presented. The curves and pH optima shifted under increasing temperatures towards lower pH values, which was verified after decomposition. Nonlinear regression detected the presence of two components for both fractions, and there is no considerable difference between their pH optima. Our results show for the first time that the sum of components, each described by the mathematical model employed, can be used to explain the complex pH-related POD activity in the extract with two or more enzyme forms simultaneously active.",
publisher = "General Physiol And Biophysics, Bratislava",
journal = "General Physiology and Biophysics",
title = "The effect of pH on the activity of soluble peroxidase in needles of Serbian spruce (Picea omorika (Panc.) Purkinye): application of a mathematical model",
pages = "128-122",
number = "2",
volume = "29",
doi = "10.4149/gpb_2010_02_122"
}

Laketa, D., Bogdanović Pristov, J., Prodanović, R., Kalauzi, A.,& Radotić, K.. (2010). The effect of pH on the activity of soluble peroxidase in needles of Serbian spruce (Picea omorika (Panc.) Purkinye): application of a mathematical model. in General Physiology and Biophysics
General Physiol And Biophysics, Bratislava., 29(2), 122-128.
https://doi.org/10.4149/gpb_2010_02_122

Laketa D, Bogdanović Pristov J, Prodanović R, Kalauzi A, Radotić K. The effect of pH on the activity of soluble peroxidase in needles of Serbian spruce (Picea omorika (Panc.) Purkinye): application of a mathematical model. in General Physiology and Biophysics. 2010;29(2):122-128.
doi:10.4149/gpb_2010_02_122 .

Laketa, Danijela, Bogdanović Pristov, Jelena, Prodanović, Radivoje, Kalauzi, Aleksandar, Radotić, Ksenija, "The effect of pH on the activity of soluble peroxidase in needles of Serbian spruce (Picea omorika (Panc.) Purkinye): application of a mathematical model" in General Physiology and Biophysics, 29, no. 2 (2010):122-128,
https://doi.org/10.4149/gpb_2010_02_122 . .

TY  - JOUR
AU  - Laketa, Danijela
AU  - Bogdanović Pristov, Jelena
AU  - Kalauzi, Aleksandar
AU  - Radotić, Ksenija
PY  - 2009
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/354
AB  - Thermal inactivation of peroxidase (POD) in an extract of Picea omorika (Pancic) Purkyne needles initiated by heat treatment was studied. This is the first study of this kind on a conifer species. Non-linear regression analysis was applied on the inactivation rate data, combining Mitscherlich and Arrhenius equations, treating time and temperature simultaneously as explaining variables. We determined the inactivation rate constant k, the Arrhenius energy of inactivation E and the remaining activity C-min for the crude extract and for separated acidic and basic enzyme fractions, as well as for individual isoenzymes separated electrophoretically. A comparison of inactivation parameters for acidic and basic fractions shows that the thermal inactivation rate of the basic fraction is higher. The obtained value of inactivation energy for crude extract was between the values for acidic and basic isoenzyme fractions. One of the three analysed individual isoenzymes was characterised by a lower inactivation rate constant and higher inactivation energy. Another isoenzyme showed considerably higher level of remaining activity compared to the others, which identified it as the most resistant to high temperatures. The acquired values of Arrhenius energy of inactivation for POD in crude extract were intermediate, considering a range of POD values for various other plant species.
PB  - General Physiol And Biophysics, Bratislava
T2  - General Physiology and Biophysics
T1  - Kinetic parameters for thermal inactivation of soluble peroxidase from needles of Serbian spruce Picea omorika (Pancic) Purkyne
EP  - 85
IS  - 1
SP  - 78
VL  - 28
DO  - 10.4149/gpb_2009_01_78
ER  - 

@article{
author = "Laketa, Danijela and Bogdanović Pristov, Jelena and Kalauzi, Aleksandar and Radotić, Ksenija",
year = "2009",
abstract = "Thermal inactivation of peroxidase (POD) in an extract of Picea omorika (Pancic) Purkyne needles initiated by heat treatment was studied. This is the first study of this kind on a conifer species. Non-linear regression analysis was applied on the inactivation rate data, combining Mitscherlich and Arrhenius equations, treating time and temperature simultaneously as explaining variables. We determined the inactivation rate constant k, the Arrhenius energy of inactivation E and the remaining activity C-min for the crude extract and for separated acidic and basic enzyme fractions, as well as for individual isoenzymes separated electrophoretically. A comparison of inactivation parameters for acidic and basic fractions shows that the thermal inactivation rate of the basic fraction is higher. The obtained value of inactivation energy for crude extract was between the values for acidic and basic isoenzyme fractions. One of the three analysed individual isoenzymes was characterised by a lower inactivation rate constant and higher inactivation energy. Another isoenzyme showed considerably higher level of remaining activity compared to the others, which identified it as the most resistant to high temperatures. The acquired values of Arrhenius energy of inactivation for POD in crude extract were intermediate, considering a range of POD values for various other plant species.",
publisher = "General Physiol And Biophysics, Bratislava",
journal = "General Physiology and Biophysics",
title = "Kinetic parameters for thermal inactivation of soluble peroxidase from needles of Serbian spruce Picea omorika (Pancic) Purkyne",
pages = "85-78",
number = "1",
volume = "28",
doi = "10.4149/gpb_2009_01_78"
}

Laketa, D., Bogdanović Pristov, J., Kalauzi, A.,& Radotić, K.. (2009). Kinetic parameters for thermal inactivation of soluble peroxidase from needles of Serbian spruce Picea omorika (Pancic) Purkyne. in General Physiology and Biophysics
General Physiol And Biophysics, Bratislava., 28(1), 78-85.
https://doi.org/10.4149/gpb_2009_01_78

Laketa D, Bogdanović Pristov J, Kalauzi A, Radotić K. Kinetic parameters for thermal inactivation of soluble peroxidase from needles of Serbian spruce Picea omorika (Pancic) Purkyne. in General Physiology and Biophysics. 2009;28(1):78-85.
doi:10.4149/gpb_2009_01_78 .

Laketa, Danijela, Bogdanović Pristov, Jelena, Kalauzi, Aleksandar, Radotić, Ksenija, "Kinetic parameters for thermal inactivation of soluble peroxidase from needles of Serbian spruce Picea omorika (Pancic) Purkyne" in General Physiology and Biophysics, 28, no. 1 (2009):78-85,
https://doi.org/10.4149/gpb_2009_01_78 . .