Range: ±0.09 pH units
||Human Homo sapiens
||Porcelli AM, Ghelli A, Zanna C, Pinton P, Rizzuto R, Rugolo M. pH difference across the outer mitochondrial membrane measured with a green fluorescent protein mutant. Biochem Biophys Res Commun. 2005 Jan 28 326(4):799-804. doi:10.1016/j.bbrc.2004.11.105 p.801 right column 2nd paragraphPubMed ID15607740
||Abstract: "In this study [investigators] have generated a EYFP targeted to the mitochondrial intermembrane space (MIMS-EYFP) to determine for the first time the pH within this compartment. The fragment encoding HAI-tagged EYFP was fused with the C-terminus of glycerol-phosphate dehydrogenase, an integral protein of the inner mitochondrial membrane. Human ECV304 cells transiently transfected with MIMS-EYFP showed the typical mitochondrial network, co-localized with MitoTracker Red. Following the calibration procedure, an estimation of the pH value in the intermembrane space was obtained."
||P.801 right column 2nd paragraph: "When the average values of fluorescence in the selected areas were plotted against pH, the calibration line shown in Fig. 2B was obtained. A similar calibration was carried out also in cells transfected with cyt-EYFP and with mt-EYFP (data not shown). With this calibration, the pH values obtained were 6.88 ± 0.09 (n = 32) in the IMS,
7.78 ± 0.17 (n = 9) in the matrix, and 7.59 ± 0.01 (n = 21) in the cytosol, as illustrated in Fig. 3."