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The “B Space” of mitochondrial phosphorylation
Author(s) -
Chinopoulos Christos
Publication year - 2011
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.22659
Subject(s) - translocase , atp synthase , mitochondrial matrix , atp–adp translocase , chemistry , biophysics , mitochondrion , inner mitochondrial membrane , membrane potential , cytosol , biology , biochemistry , enzyme , chromosomal translocation , gene
It was recently shown that, in progressively depolarizing mitochondria, the F 0 ‐F 1 ATP synthase and the adenine nucleotide translocase (ANT) may change directionality independently from each other (Chinopoulos et al. [2010] FASEB J. 24:2405). When the membrane potentials at which these two molecular entities reverse directionality, termed reversal potential (Erev), are plotted as a function of matrix ATP/ADP ratio, an area of the plot is bracketed by the Erev_ATPase and the Erev_ANT, which we call “B space”. Both reversal potentials are dynamic, in that they depend on the fluctuating values of the participating reactants; however, Erev_ATPase is almost always more negative than Erev_ANT. Here we review the conditions that define the boundaries of the “B space”. Emphasis is placed on the role of matrix substrate‐level phosphorylation, because during metabolic compromise this mechanism could maintain mitochondrial membrane potential and prevent the influx of cytosolic ATP destined for hydrolysis by the reversed F 0 ‐F 1 ATP synthase. © 2011 Wiley‐Liss, Inc.