Dharmaraj K, Román Silva JI, Kahlert H, Lendeckel U, Scholz F. The acid-base and redox properties of menaquinone MK-4, MK-7, and MK-9 (vitamin K
2) in DMPC monolayers on mercury.
EUROPEAN BIOPHYSICS JOURNAL: EBJ 2020;
49:279-288. [PMID:
32372117 PMCID:
PMC7244470 DOI:
10.1007/s00249-020-01433-0]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 03/16/2020] [Accepted: 04/20/2020] [Indexed: 01/07/2023]
Abstract
Abstract
The acid–base and redox properties of the menaquinones MK-4, MK-7, and MK-9 (vitamin K2) have been studied in DMPC monolayers on mercury electrodes. The monolayers were prepared by adhesion-spreading of menaquinone-spiked DMPC liposomes on a stationary mercury drop electrode. All three menaquinones possess \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$${\text{p}}K_{{\text{a}}}$$\end{document}pKa constants outside the experimentally accessible range, i.e., they are higher than about 12. The standard potentials of MK-4, MK-7, and MK-9 in the DMPC monolayers are very similar, i.e., 0.351, 0.326, and 0.330 V (corresponding to the biochemical standard potentials − 0.063, − 0.088, and − 0.085 V).
Graphic abstract
![]()
Collapse