Determination of proton concentration at cardiolipin-containing membrane interfaces and its relation with the peroxidase activity of cytochrome c.

ABSTRACT: The activities of biomolecules are affected by the proton concentrations at biological membranes. Here, we succeeded in evaluating the interface proton concentration (-log[H⁺] defined as pH') of cardiolipin (CL)-enriched membrane models of the inner mitochondrial membrane (IMM) using a spiro-rhodamine-glucose molecule (RHG). According to fluorescence microscopy and ¹H-NMR studies, RHG interacted with the Stern layer of the membrane. The acid/base equilibrium of RHG between its protonated open form (o-RHG) and deprotonated closed spiro-form (c-RHG) at the membrane interface was monitored with UV-vis absorption and fluorescence spectra. The interface pH' of 25% cardiolipin (CL)-containing large unilamellar vesicles (LUVs), which possess similar lipid properties to those

SUBMITTER: Parui PP 

PROVIDER: S-EPMC6889831 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature