Nigericin

high-resolution terminology - matching measurements at high-resolution

Nigericin

Description

Nigericin is a H⁺/K⁺ antiporter, which allows the electroneutral transport of these two ions in opposite directions across the mitochondrial inner membrane following the K⁺ concentration gradient. In the presence of K⁺, nigericin decreases pH in the mitchondrial matrix, thus, almost fully collapses the transmembrane ΔpH, which leads to the compensatory increase of the electric mt-membrane potential. Therefore, it is ideal to use to dissect the two components of the protonmotive force, ΔpH and mt-membrane potential. It is recommended to use the lowest possible concentration of nigericin, which creates a maximal mitochondrial hyperpolarization. In the study of Komlodi 2018 J Bioenerg Biomembr, 20 nM was applied on brain mitochondria isolated from guinea-pigs using 5 mM succinate in the LEAK state which caused maximum hyperpolarisation, but did not fully dissipate the transmembrane ΔpH. Other groups (Selivanov et al 2008; Lambert et al 2004), however, used 100 nM nigericin, which in their hands fully collapsed transmembrane ΔpH using succinate as a respiratory substrate on isolated rat brain and skeletal muscle in the LEAK state.

Reference: Dalmonte_2009_J_Biol_Chem; Komlodi 2018 J Bioenerg Biomembr; Selivanov 2008 J Biol Chem; Lambert 2004 Biochem J; Komlodi 2022 BEC

MitoPedia concepts: Respiratory state 

MitoPedia methods: Respirometry, Fluorometry