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The use of microcalorimetric methods in the study of the protective effects of chemical chaperons
Bohunská, Miroslava ; Pekař, Miloslav (referee) ; Krouská, Jitka (advisor)
This bachelor thesis deals with the study of protective substances against denaturation processes, called chemical chaperones. The theoretical part describes the general characteristics of proteins, description of selected chaperones and methods of differential scanning calorimetry. In the experimental part, the protective effects of four potential protective agents - trehalose, guanidine hydrochloride, 3-hydroxybutyrate and hydroxyectoine - were investigated on the lysozyme model protein. The protective effects of the individual substances were examined by differential scanning calorimetry (DSC), which determined the denaturation temperature of lysozyme in the presence of preservatives. Of all the chemical chaperones examined, the highest protective effect was observed with 3-hydroxybutyrate, which shifted the denaturation temperature to higher levels, and guanidine hydrochloride, which on the other hand lowered the denaturation temperature. At the same time, a reversible denaturation process was found in some substances, which was the most intense in GuHCl.
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Study of interactions of the surfactant component of Septonex with selected proteins
Bohunská, Miroslava ; Pekař, Miloslav (referee) ; Krouská, Jitka (advisor)
The study of protein and surfactant interactions is of great significance in a number of applications, such as the cosmetic, food or pharmaceutical industries and many others. However, they require further study due to their compositional complexity and the limitations of current analytical approaches. In this thesis, the cationic surfactant septonex in combination with two differently charged proteins lysozyme and bovine serum albumin under different physiological conditions (temperature, surfactant concentration, environment and others) was selected to study the interactions. Characterization of protein-surfactant interactions is a very important but challenging task, therefore it is essential to use appropriate approaches to explore the nature of these interactions. In order to unify the information to provide rational models, calorimetric methods (DSC, ITC) and dynamic light scattering were used. Isothermal titration calorimetry monitors the evidence for the formation of the system of the mentioned substances and information on aggregation behavior, differential scanning calorimetry characterizes the thermal stability of proteins and dynamic light scattering made it possible to monitor changes in particle size. Both proteins have been proven to interact with positive septonex, even if the lysozyme molecule is also positively charged. However, significant differences were found between the two proteins. From the obtained results it is evident that the identical charge of the protein with the surfactant has an effect on the intensity of the measurement, although all measured interactions showed an endothermic character.
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Study of interactions of the surfactant component of Septonex with selected proteins
Bohunská, Miroslava ; Pekař, Miloslav (referee) ; Krouská, Jitka (advisor)
The study of protein and surfactant interactions is of great significance in a number of applications, such as the cosmetic, food or pharmaceutical industries and many others. However, they require further study due to their compositional complexity and the limitations of current analytical approaches. In this thesis, the cationic surfactant septonex in combination with two differently charged proteins lysozyme and bovine serum albumin under different physiological conditions (temperature, surfactant concentration, environment and others) was selected to study the interactions. Characterization of protein-surfactant interactions is a very important but challenging task, therefore it is essential to use appropriate approaches to explore the nature of these interactions. In order to unify the information to provide rational models, calorimetric methods (DSC, ITC) and dynamic light scattering were used. Isothermal titration calorimetry monitors the evidence for the formation of the system of the mentioned substances and information on aggregation behavior, differential scanning calorimetry characterizes the thermal stability of proteins and dynamic light scattering made it possible to monitor changes in particle size. Both proteins have been proven to interact with positive septonex, even if the lysozyme molecule is also positively charged. However, significant differences were found between the two proteins. From the obtained results it is evident that the identical charge of the protein with the surfactant has an effect on the intensity of the measurement, although all measured interactions showed an endothermic character.
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The use of microcalorimetric methods in the study of the protective effects of chemical chaperons
Bohunská, Miroslava ; Pekař, Miloslav (referee) ; Krouská, Jitka (advisor)
This bachelor thesis deals with the study of protective substances against denaturation processes, called chemical chaperones. The theoretical part describes the general characteristics of proteins, description of selected chaperones and methods of differential scanning calorimetry. In the experimental part, the protective effects of four potential protective agents - trehalose, guanidine hydrochloride, 3-hydroxybutyrate and hydroxyectoine - were investigated on the lysozyme model protein. The protective effects of the individual substances were examined by differential scanning calorimetry (DSC), which determined the denaturation temperature of lysozyme in the presence of preservatives. Of all the chemical chaperones examined, the highest protective effect was observed with 3-hydroxybutyrate, which shifted the denaturation temperature to higher levels, and guanidine hydrochloride, which on the other hand lowered the denaturation temperature. At the same time, a reversible denaturation process was found in some substances, which was the most intense in GuHCl.
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