Biochemistry
Nayere Bahamin; Behzad Sareghi
Articles in Press, Accepted Manuscript, Available Online from 19 October 2014
Abstract
In this study, the interaction of various concentrations of Cadmium Sulfate with Peroxidase (E.C 1.11.1.7) was investigated in different temperatures (25-35 °C). For this purpose thermostability, spectrophotometry, spectroflorimetry and kinetics studies were done to obtain thermodynamic parameters including ...
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In this study, the interaction of various concentrations of Cadmium Sulfate with Peroxidase (E.C 1.11.1.7) was investigated in different temperatures (25-35 °C). For this purpose thermostability, spectrophotometry, spectroflorimetry and kinetics studies were done to obtain thermodynamic parameters including ∆G°, ∆H°m, ∆S°m, Tm and also kinetics parameters including Vmax and Km. The results showed that Cadmium Sulfate caused uncompetitive inhibition at different temperatures and increasing of temperature intensified this inhibition effect. Also Cadmium Sulfate was reduced the stability of peroxidase and reduced its Tm. In the spectrophotometric studies the effect of Cadmium Sulfate on the peroxidase in such a way that the absorption in 275nm increased and temperatures increased it too, also the absorption in 404nm (soret bond) decreased and temperature decreased it too. Totally, Cadmium Sulfate ions in a time- and dose- dependent manner and affected by temperature bind to the peroxidase in the heme environment and decrease the thermostability of it, and exert uncompetitive inhibition.
Shahrzad Fouladi; Reza Haji Hosseini; Masoud Torkzadeh; Hooshang Hamidian
Abstract
Ionic liquids (ILs) are salts that can affect the structure, stability, and function of proteins. Researchers have recently been interested in finding ionic liquids that increase the stability, activity and solubility of enzymes. In this study, efforts are made to investigate the effect of triethylammonium ...
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Ionic liquids (ILs) are salts that can affect the structure, stability, and function of proteins. Researchers have recently been interested in finding ionic liquids that increase the stability, activity and solubility of enzymes. In this study, efforts are made to investigate the effect of triethylammonium propionate (TEAP) on the function of urate oxidase (UOX). We treated the enzyme in different concentrations of TEAP. The volume percentages of TEAP in the solvent phase are 0.5%, 1%, 2%, 5%, 10% and 15%. The results indicate that TEAP has a concentration-dependent effect on the activity of UOX enzyme. The use of 1% TEAP ionic liquid increased the enzymatic activity in comparison to untreated enzyme. We concluded that this ionic liquide was able to alter the structure of the uricase in a way that increased the activity and improve its catalytic efficiency of the enzyme. Also the thermodynamic prameters such as ΔG#, ΔH#, and ΔS# values indicate that the use of 1% of triethylammonium propionate increases the thermostability of uricase and reduces the conformational changes of this enzyme during thermal inactivation process.
