Partial filling affinity capillary electrophoresis applied to the study of noncovalent interactions of human insulin with biolgically relevant ligands

0538655 - ÚOCHB 2021 CZ eng A - Abstrakt
Šolínová, Veronika - Žáková, Lenka - Jiráček, Jiří - Kašička, Václav
Partial filling affinity capillary electrophoresis applied to the study of noncovalent interactions of human insulin with biolgically relevant ligands.
Czech Chemical Society Symposium Series. Roč. 18, č. 3 (2020), s. 83. ISSN 2336-7202.
[Sjezd českých a slovenských chemických společností /72./. 06.09.2020-09.09.2020, Praha]
Grant CEP: GA ČR(CZ) GA18-02597S
Institucionální podpora: RVO:61388963
Klíčová slova: affinity capillary electrophoresis * human insulin * noncovalent interactions
Obor OECD: Analytical chemistry
https://sjezd72.csch.cz/wp-content/uploads/2020/09/Sjezd-Praha-2020-tisk.pdf

A new method, pressure assisted partial filling affinity capillary electrophoresis (PF-ACE), has been developed to study noncovalent interactions of the hexamer of human insulin (HI) with biologically relevant ligands, such as cationic phenolic and amino acid neurotransmitters (serotonin, dopamine, nor-epinephrine, epinephrine, and Arg) or anionic ligands (phenol, L-DOPA, and Trp) in alkaline aqueous solutions. HI is one of the key protein hormones controlling metabolism, growth, and ageing1 . Its malfunction causes diabetes, cancer and Alzheimer`s disease. HI is a 51-amino acid protein consisting of two disulfide-linked chains. Phenolic neurotransmitters were found to be present in insulin secretory granules in pancreatic β-cells; it was proposed that their binding can induce different oligomeric states and conformations of HI. Arg can be abundant in secretory granules as a product of proinsulin processing; it is known as an effective inducer of HI secretion. The apparent binding constants, Kb, 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 dissolved in the background electrolyte (BGE) and hydrodynamically introduced into the fused silica capillary close to the UV detector. The strong cationic electroosmotic flow in alkaline BGEs, pH 8.1 or 8.5, had to be reduced by 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 capillary2 . The HI interactions with the above ligands were found to be moderately strong, with Kb values in the range 385–1314 L/mol. From the above eight ligands, phenol and Trp were the strongest binders of HI whereas the strongly basic amino acid Arg formed with HI the weakest complex.
Trvalý link: http://hdl.handle.net/11104/0316946