Mine M, Mizuguchi H, Takayanagi T. Kinetic analysis of substrate competition in enzymatic reactions with β-D-galactosidase by capillary electrophoresis / dynamic frontal analysis.
J Pharm Biomed Anal 2020;
188:113390. [PMID:
32512255 DOI:
10.1016/j.jpba.2020.113390]
[Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 02/01/2023]
Abstract
Competitive inhibition between two substrates with an enzyme is investigated by capillary electrophoresis/dynamic frontal analysis (CE/DFA). Enzymatic hydrolyses of o-nitrophenyl β-D-galactopyranoside and p-nitrophenyl β-D-galactopyranoside with β-D-galactosidase were examined as a model competitive reaction. A sample solution containing the two substrates was injected into a capillary filled with a separation buffer containing an enzyme. Enzymatic hydrolysis occurred during the electrophoresis, and the products of o-nitrophenol and p-nitrophenol were continuously formed and resolved from the sample zone. Two-steps plateau signal was detected with the two-substrate solutions based on the difference in the effective electrophoretic mobility of o-nitrophenol and p-nitrophenol. Michaelis-Menten constants and inhibition constants were determined with the plateau heights. Usefulness of CE/DFA on competitive inhibition analysis is demonstrated in this study.
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