Quantitative Analysis of Mitochondrial Membrane Potential Measurements with JC‐1

Abstract

To guide quantitative investigations into the regulation of mitochondrial metabolism, a computational model that simulates underlying chemical kinetics and thermodynamics of the mitochondrial respiratory chain and oxidative phosphorylation was developed It has been successfully extended to analyze mitochondrial membrane potential measurements with rhodamine 123, one of the most used potential sensitive probes Another dye that is rapidly gaining popularity is JC-1. Its wide application is attributed to its visually appealing dual color detection due to fluorescence emission of both green monomer and red J-aggregates in differential response to membrane potential changes. Although response of the fluorescence signal to membrane potential changes has been calibrated, the lack of consistency, of biophysical understanding of how membrane potential and measured fluorescence are related and how the relationship is impacted by different factors, has limited the quantitative application of the dye. Here we integrate the JC-1 transport, aggregation, quenching and partition into the membrane into the mitochondrial model. The model simulation is consistent with experimental observations. This study provides a useful theoretical framework for experimental design and assessment of both static and transient membrane potential using JC-1. Beard DA. A biophysical model of the mitochondrial respiratory chain and oxidative phosphorylation. PLOS Computational Biology, 2005 Huang M, Camara A, DF Stowe, Qi F, Beard DA. Mitochondrial Inner Membrane Electrophysiology Assessed by Rhodamine-123 Transport and Fluorescence. (in review; available on-line). This work is supported by NIH grant HL072011