Behzad Shareghi; Maryam Kazemi Nafchi
Volume 6, Issue 4 , June 2018, , Pages 23-33
Abstract
Abstract Peroxidases are a group of oxidoreductases that are produced by a number of microorganisms and plants, and catalyse the reduction of peroxides. Peroxidases are widely used in clinical biochemistry and enzyme immunoassay. Horseradish peroxidase isoenzyme C (HRPC) is one of the characterized peroxidases. ...
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Abstract Peroxidases are a group of oxidoreductases that are produced by a number of microorganisms and plants, and catalyse the reduction of peroxides. Peroxidases are widely used in clinical biochemistry and enzyme immunoassay. Horseradish peroxidase isoenzyme C (HRPC) is one of the characterized peroxidases. The structure of the enzyme is largely alpha helical. Peroxidase enzyme is detox important enzyme that to work process for getting rid of the cells of additional hydrogen peroxide under normal and stress conditions, including contamination with toxic levels of heavy metals, however, severe stress possible influence upon the activity of detoxification enzyme. Kinetics studies of peroxidase enzyme were performed using a spectrophotometer UV-Vis fitted with electronic control system at 35 °C and 45 °C and pH4 and in the presence ferric oxide and copper oxide. Kinetic parameters show that ferric oxide and copper oxide becomes caused the decrease of maximum speed (VMAX) and activity of the enzyme. Likely due to the ferri and copper ions have positively charged, these places are on or near the sites of glycosylation of enzyme and by their negatively charged are suitable binding sites for iron and copper. Likely binding of iron and copper are caused more changes of the secondary structure and makes random coil deduction more than alpha helix.
Behzad* shareghi; Sakineh Sadeghi kaji
Volume 5, Issue 3 , March 2017, , Pages 1-8
Abstract
Urease (urea amidohydrolase, EC 3.5.1.5) catalyzes the hydrolysis of urea to produce ammonia and CO2. Kinetics studies have been performed using UV-vis spectrophotometer at 40oC and pHs 5.5, 7.2, 8. Result showed that urease inhibition by hydrogen peroxide is a kinetics pH-dependent, such that inhibition ...
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Urease (urea amidohydrolase, EC 3.5.1.5) catalyzes the hydrolysis of urea to produce ammonia and CO2. Kinetics studies have been performed using UV-vis spectrophotometer at 40oC and pHs 5.5, 7.2, 8. Result showed that urease inhibition by hydrogen peroxide is a kinetics pH-dependent, such that inhibition is maximal on the condition of pH value 8 while the inhibitory effect hydrogen peroxide at pH 5.5 was minimum. The kinetic parameters Km and Vmax enzyme obtained from Lineweaver–Burk plot in absence of hydrogen peroxide was 4.52mM and 1.03mM.min-1 respectively .In presence of H2O2, increasing pH leads to decrease Vmax and km. The results showed that in pH 8, boric acid and β-mercaptho ethanol protected urease against hydrogen peroxide. Protectable of β-mercaptho ethanol is more than of boric acid. Such, the results demonstrates that 30 mM boric acid and β-mercaptho ethanol afforded to protect 80% and 90% of urease activity from the loss as compared to the respective control samples
Behzad Shareghi; Maryam Kazemi Nafchi
Volume 5, Issue 1 , September 2016, , Pages 1-8
Abstract
Abstract Peroxidases are a group of oxidoreductases that are produced by a number of microorganisms and plants, and catalyse the reduction of peroxides. Peroxidases are widely used in clinical biochemistry and enzyme immunoassay. Horseradish peroxidase isoenzyme C (HRP) is one of the characterized peroxidases. ...
Read More
Abstract Peroxidases are a group of oxidoreductases that are produced by a number of microorganisms and plants, and catalyse the reduction of peroxides. Peroxidases are widely used in clinical biochemistry and enzyme immunoassay. Horseradish peroxidase isoenzyme C (HRP) is one of the characterized peroxidases. The structure of the enzyme is largely alpha helical. Kinetics studies of peroxidase enzyme were performed using a spectrophotometer UV-Vis fitted with electronic control system at 35oC and 45oC and pH4 and in the presence ethanol and butanediol. Kinetic parameters show that ethanol and butanediol organic solvents becomes caused the increase of maximum speed (VMAX) and activity of the enzyme. Organic solvents have effect on electrostatic interactions of proteins because their dielectric constant with water is different. In general, reduce properties of polar solvents and decreased dielectric constant becomes caused the increases electrostatic repulsion, leading to the opening of the proteins. Enzymes activity in such organic environments increases stability, activity or facilitate reactions that are difficult to perform in aquatic environments.
