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The use of protein radical footprinting by Togni reagents in structural biology
Fojtík, Lukáš ; Kukačka, Zdeněk (advisor) ; Kolenko, Petr (referee)
Structural proteomic methods such as an ion mobility mass spectrometry, chemical cross- linking or covalent labeling have been established as powerful tools for structural studies of biomolecules in general. These methods have significantly contributed to the expansion of our knowledge about biomolecular functions, their dynamics and molecular interactions and therefore led to the understanding of important biological processes occurring in a cell. We decided to spread these methods and we developed a new radical labeling technique relaying on Fluor-alkyl radicals that does not require a laser dissociation pf hydrogen peroxide. We exploited the potential of Togni reagents to form Fluor-alkyl radicals by reducing agent under native conditions. The induction of Fluor-alkyl radicals was triggered by ascorbic acid and the labeling pulse was stopped by tryptophan. The modified proteins were analyzed by top down or bottom up approach using high resolution mass spectrometry. In case of top down approach, several fragmentation techniques (CID-ECD, ETD) were tested for protein analysis while in case of bottom up approach the analyzed proteins were digested by trypsin and separated on reverse phase column online coupled to mass spectrometer. As the model biomolecules we chose a 20 proteinogenic amino acids...
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Protein radical footprinting as a tool for protein therapeutcs validation.
Binar, Michal ; Novák, Petr (advisor) ; Ječmen, Tomáš (referee)
Mass spectrometry techniques are very important and useful tool in studying of protein structure. One of these techniques is the covalent labeling of proteins. The covalent labeling can be used for determination of the accessibility of protein surface and their dynamics in general. Although a lot of reagents have already been developer for this method, most of them are limited by their ability to selectively react with only some of amino acids, mostly lysine, arginine or tyrosine, and non-selective methods such as fast photochemical oxidation of proteins are very demanding and costly. Therefore, there is still a endeavor to develop new methods of covalent labeling. This new method could be trifluoromethylation, which is increasingly used in the modification of organic molecules, and whose potential we have decided to study. In this work we used a new group of formally electrophilic agents, which is formed on the basis of a cyclic hypervalent iodide nucleus. This group so-called Togni reagents was used as a tool for radical protein labeling. Since the structure was well characterized by X-ray, NMR and MS, the human carbonic anhydrase has been selected as a model protein. The modified protein was analyzed by a bottom up approach using a combination of liquid chromatography and high resolution tandem...
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The use of protein radical footprinting by Togni reagents in structural biology
Fojtík, Lukáš ; Kukačka, Zdeněk (advisor) ; Kolenko, Petr (referee)
Structural proteomic methods such as an ion mobility mass spectrometry, chemical cross- linking or covalent labeling have been established as powerful tools for structural studies of biomolecules in general. These methods have significantly contributed to the expansion of our knowledge about biomolecular functions, their dynamics and molecular interactions and therefore led to the understanding of important biological processes occurring in a cell. We decided to spread these methods and we developed a new radical labeling technique relaying on Fluor-alkyl radicals that does not require a laser dissociation pf hydrogen peroxide. We exploited the potential of Togni reagents to form Fluor-alkyl radicals by reducing agent under native conditions. The induction of Fluor-alkyl radicals was triggered by ascorbic acid and the labeling pulse was stopped by tryptophan. The modified proteins were analyzed by top down or bottom up approach using high resolution mass spectrometry. In case of top down approach, several fragmentation techniques (CID-ECD, ETD) were tested for protein analysis while in case of bottom up approach the analyzed proteins were digested by trypsin and separated on reverse phase column online coupled to mass spectrometer. As the model biomolecules we chose a 20 proteinogenic amino acids...
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|
|
Protein radical footprinting as a tool for protein therapeutcs validation.
Binar, Michal ; Novák, Petr (advisor) ; Ječmen, Tomáš (referee)
Mass spectrometry techniques are very important and useful tool in studying of protein structure. One of these techniques is the covalent labeling of proteins. The covalent labeling can be used for determination of the accessibility of protein surface and their dynamics in general. Although a lot of reagents have already been developer for this method, most of them are limited by their ability to selectively react with only some of amino acids, mostly lysine, arginine or tyrosine, and non-selective methods such as fast photochemical oxidation of proteins are very demanding and costly. Therefore, there is still a endeavor to develop new methods of covalent labeling. This new method could be trifluoromethylation, which is increasingly used in the modification of organic molecules, and whose potential we have decided to study. In this work we used a new group of formally electrophilic agents, which is formed on the basis of a cyclic hypervalent iodide nucleus. This group so-called Togni reagents was used as a tool for radical protein labeling. Since the structure was well characterized by X-ray, NMR and MS, the human carbonic anhydrase has been selected as a model protein. The modified protein was analyzed by a bottom up approach using a combination of liquid chromatography and high resolution tandem...
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