|
|
Characterization of low-molecular-mass synthetic markers of isoelectric points by capillary zone electrophoresis and capillary isoelectric focusing
Brandejsová, Martina ; Kašička, Václav (advisor) ; Kubíčková, Anna (referee)
High-performance electromigration separation methods, capillary zone electrophoresis (CZE) and capillary isoelectric focusing (CIEF), have been applied to physico-chemical characterization of new synthetic low-molecular mass markers of isoelectric points. Amphoteric compounds on the basis of aminomethylnitrophenols, their derivatives and other structurally related substances were analyzed by CZE in a series of background electrolytes in a wide pH range, 1.86 - 11.18. From the measured pH dependencies of effective electrophoretic mobilities of analytes (beforehand corrected to reference temperature of 25 řC), their isoelectric points (pI) were determined. In addition, using the non-linear regression analysis of the above dependencies, acid-base dissociation constants (pKa) of ionogenic groups of selected analytes were calculated. Subsequently, the analytes with sharply defined isoelectric points were analyzed by CIEF. CIEF confirmed applicability of these compounds as markers of isoelectric points for calibration of pH gradient in CIEF in the determination of pI of amphoteric compounds, especially peptides and proteins. The determined pKa values of ionogenic groups in particular compounds will be utilized in the development of new pI markers with desired pI values.
|
|
|
Evaluation of the 33 synthesized nitrophenol-based markers of isoelectic point
Duša, Filip ; Moravcová, Dana ; Šlais, Karel
33 nitrophenol-based compounds, which absorb at ultraviolet as well as visible wavelengths, were selected as candidates for marking isoelectric points (pI) over the pH range from 3 to 10. The evaluation and selection of the candidate structures included structure-based calculations of acid-base properties. The selected compounds were further tested experimentally using capillary isoelectric focusing. The experimental analysis excluded two compounds due to producing double peaks during the analysis. Overall, 31 novel compounds were identified as suitable pI markers.
|
|
|
Characterization of low-molecular-mass synthetic markers of isoelectric points by capillary zone electrophoresis and capillary isoelectric focusing
Brandejsová, Martina ; Kašička, Václav (advisor) ; Kubíčková, Anna (referee)
High-performance electromigration separation methods, capillary zone electrophoresis (CZE) and capillary isoelectric focusing (CIEF), have been applied to physico-chemical characterization of new synthetic low-molecular mass markers of isoelectric points. Amphoteric compounds on the basis of aminomethylnitrophenols, their derivatives and other structurally related substances were analyzed by CZE in a series of background electrolytes in a wide pH range, 1.86 - 11.18. From the measured pH dependencies of effective electrophoretic mobilities of analytes (beforehand corrected to reference temperature of 25 řC), their isoelectric points (pI) were determined. In addition, using the non-linear regression analysis of the above dependencies, acid-base dissociation constants (pKa) of ionogenic groups of selected analytes were calculated. Subsequently, the analytes with sharply defined isoelectric points were analyzed by CIEF. CIEF confirmed applicability of these compounds as markers of isoelectric points for calibration of pH gradient in CIEF in the determination of pI of amphoteric compounds, especially peptides and proteins. The determined pKa values of ionogenic groups in particular compounds will be utilized in the development of new pI markers with desired pI values.
|
|
| |
|
|
Filtration microcartridge and capillary isoelectric focusing for the analysis low number of microorganisms in real samples
Kubesová, Anna ; Horká, Marie ; Šalplachta, Jiří ; Horký, J.
At present, detection and identification of microorganisms in real biological samples needs very sensitive methods for correct diagnosis and therapy in medical practice, biotechnology, agriculture, food safety and quality etc. Accordingly, it is essential to develop new cheap techniques for pathogen identification, particularly for pathogen in complex biological samples. Pre-concentration, separation, and sensitive detection of whole cells in one step are great potential and advantage for detection of pathogens in low concentration. Combination of filtration microcartridge and capillary isoelectric focusing was developed for pre-concentration and pre-separation of microorganisms from real suspensions and the possibility its application to real samples was verified.
|
|
|
Standards for capillary isoelectric focusing with laser induced fluorescence detection
Šlais, Karel ; Nováčková, J. ; Friedl, Z.
Proteins, peptides or BGE ampholytes labeled with suitable dyes were previously suggested as pI markers. However, both proteins and background ampholytes have many possible reactive sites for reactive dyes and this might result in formation of heterogeneously labeled product with respect to pI. By contrast, the low molecular pI markers can be prepared with heterogeneity and greater stability than proteins and could potentially be good pI markers as found in case of UV detection. To improve the laser induced fluorescence detection, new low molecular fluorescent compounds excitable around 490 nm with suitable acidobasic and electrophoretic properties were prepared and focused in capillary IEF with photometric or fluorometric detection. The experimental setup of IEF and properties of new laser induced fluorescent pI markers are given.
|
guest ::
