Pressure assisted partial filling affinity capillary electrophoresis employed for determination of binding constants of human insulin hexamer complexes with serotonin, dopamine, arginine, and phenol

0501552 - ÚOCHB 2020 RIV NL eng J - Journal Article
Šolínová, Veronika - Žáková, Lenka - Jiráček, Jiří - Kašička, Václav
Pressure assisted partial filling affinity capillary electrophoresis employed for determination of binding constants of human insulin hexamer complexes with serotonin, dopamine, arginine, and phenol.
Analytica Chimica Acta. Roč. 1052, Apr 4 (2019), s. 170-178. ISSN 0003-2670. E-ISSN 1873-4324
R&D Projects: GA ČR(CZ) GA17-10832S; GA ČR(CZ) GA18-02597S; GA MŠMT(CZ) EF16_019/0000729
Institutional support: RVO:61388963
Keywords : affinity capillary electrophoresis * binding constant * human insulin * insulin hexamer * neurotransmitters * partial filling
OECD category: Analytical chemistry
Impact factor: 5.977, year: 2019
Method of publishing: Limited access
https://www.sciencedirect.com/science/article/pii/S0003267018313655?via%3Dihub

A new method, pressure assisted partial filling affinity capillary electrophoresis, has been developed to study noncovalent molecular interactions of the hexamer of human insulin (HI) with biologically relevant ligands, basic phenolic neurotransmitters serotonin and dopamine, basic amino acid arginine, and very weakly acidic phenol, in alkaline aqueous media. The apparent binding constants, K-b, of the HI-ligand complexes were determined from the dependence of the effective migration time changes of the above ligands on the variable zone lengths of HI hexamer dissolved in the background electrolyte (BGE) and hydrodynamically introduced into the bare fused silica capillary close to the UV detector. The strong cationic electroosmotic flow (EOF) in alkaline BGEs, 40/40 mM Tris/tricine, pH 8.1, and 25/34 mM NaOH/tricine, pH 8.5, with EOF mobilities 52.0 x 10(-9) and 58.0 x 10(-9) m(2)V(-1)s(-1), respectively, was reduced by the hydrodynamic counter flow induced by external pressure at the outlet capillary end to avoid expulsion of HI zone out of the capillary and to allow HI interaction with both cationic and anionic ligands inside the capillary. The HI hexamer interactions with the above ligands were found to be weak to moderately strong, with K-b values in the range 385-1314 L mol(-1), and decreasing in the order HIphenol > HI-dopamine > HI-serotonin > HI-arginine.
Permanent Link: http://hdl.handle.net/11104/0296324