Analysis and characterization of antimicrobial peptides by capillary electromigration methods

0538687 - ÚOCHB 2021 CZ eng A - Abstract
Kašička, Václav - Tůmová, Tereza - Monincová, Lenka - Čeřovský, Václav
Analysis and characterization of antimicrobial peptides by capillary electromigration methods.
Czech Chemical Society Symposium Series. Roč. 18, č. 3 (2020), s. 68. ISSN 2336-7202.
[Sjezd českých a slovenských chemických společností /72./. 06.09.2020-09.09.2020, Praha]
R&D Projects: GA ČR(CZ) GA18-02597S
Institutional support: RVO:61388963
Keywords : antimicrobial peptides * capillary electrophoresis * capillary isotachophoresis
OECD category: Analytical chemistry
https://sjezd72.csch.cz/wp-content/uploads/2020/09/Sjezd-Praha-2020-tisk.pdf

High-performance capillary electromigration methods, zone electrophoresis (CZE) and isotachophoresis (CITP), have been employed for qualitative and quantitative analysis and physicochemical characterization of polycationic antimicrobial peptides (AMPs) isolated from the venom of two species of Hymenoptera insects. These AMPs are composed of 10–20 amino acids (AAs) with 3 to 7 basic AAs (His, Lys, Arg). Purity degree of synthetic AMPs was quantified by CZE in acidic background electrolytes (BGEs) using capillary coatings with cationic surfactants or polymers suppressing peptide sorption to the capillary wall. Acid-base and electromigration properties of the AMPs were investigated by combination of CZE and CITP. First, the mixed acidity constants, pKa,mix, and the actual ionic mobilities of the AMPs were estimated by nonlinear regression analysis of the pH dependence of their effective mobilities measured in series of BGEs within wide pH range (1.80–12.10), at constant ionic strength (25 mM) and temperature (25 °C). Then, the pKa,mix values were recalculated to the thermodynamic pKas using the DebyeHückel equation for activity coefficients. Effective charge of the AMPs was estimated by CITP. This approach is based on the linear dependence of the CITP zone length of the analyte on its effective charge and injected substance amount. Cationic CITP systems with leading electrolyte (LE) composed of 10 mM ammonium leading ion, 40 mM acetate counterion, pH 4.1, and terminating electrolyte containing 40 mM acetic acid, pH 3.2, provided sharp AMPs zones with good linearity and repeatability of their lengths. Ionic mobilities of AMPs were determined by CZE in the BGE of the same composition as the LE. Using this procedure, the effective charge numbers of the AMPs were found to be in the range 1.65–5.04, i.e. much less than the theoretical charge numbers (2.86–6.99) calculated from the pKa values.
Permanent Link: http://hdl.handle.net/11104/0316953