Study On The Capillary Electrophoresis Bahaviors Of Some Bioactive Peptides

Bioactive peptide is a kind of compounds which have important biological functions in the living organisms. The study on the bioactive peptides is a hot topic in the neurophysiology, pharmacology and clinical fields. It is of great significance to develop sensitive, high efficient, rapid and simple methods for the separation and determination of bioactive peptides.Four parts are included in this thesis. The first part is a review of the progress in the analysis of bioactive peptides, some physiological function and their applications. The emphases are about the capillary electrophoresis behaviors of peptides. The second part is the studies on capillary eletrophoresis methods for the separation and determination enkephalin-related peptides. A CE-UV method was developed for the separation and determination often enkephalin-related peptides in human cerebrospinal fluids (CSF). All analytes were baseline separated within 20 minutes with detection limit in the uM range. A method based on the micellar electrokinetic chromatography with laser induced fluorescence detection (MEKC-LIF) using fluorescein isothiocyanate as precapillary derivatizing reagent has been developed for separation and detection of the eight enkephalin-related peptides. The investigated compounds were well-separated with detection limit of 0.1 nM range. The kinetics of derivatization reaction was also studied using CE-UV methods and the kinetic constant was obtained. All these results provide theory foundation and experimental methods for neurophysiology and pharmacology.The third part is focused on the investigation of CE-LIF method and some on-line sample stacking methods for the carnosine-related peptides. Using 3-(4-carboxybenzoyl) quinoline-2-carboxaldehyde as pre-capillary derivatizing reagent, a CE-LIF method was established for the three carnosine-related peptides. The analytes were well separated within 20 minutes with detection limit of nM range. The proposed method has been successfully applied to analysis of human CSF and meat dry powder of pig and sheep.Three on-line sample stacking methods, such as large volume stacking with reverse pressure, large volume stacking using EOF as a pump and field-amplified injection were studied and optimatized for the analysis of carnosine-related peptides. The sensitivity was improved more than two magnitudes compared to the normal CZE. This work broadened the application of CE-UV method in the trace analysis. The methods have been proved to be simple and sensitive and provided an important analytical tool for the clinical diagnosis.The fouth part is focused on the studies of capillary electrophoresis behaviors of tyrosine and its derivatives and behaviors of capillary eletrophoresis of reduced and oxidized glutathione. Seven tyrosine and its related derivatives was well separated using CZE-UV within 20 minutes with detection limit of u,M range. The interaction between p-hydroxyphenylpyruvic acid and p-cyclodextrin is investigated by electrochemical method. The kinetics of keto-enol tautomerization of p- hydroxyphenylpyruvic acid is also studied and it has been proved to be a first-order reaction. Kinetic constant is measured. A CE-UV method for separation and determination of reduced and oxidized glutathione has been applied to the determination of glutathion in some fruits with satisfactory results.