Rj. Burns et al., SYNTHESIS AND CHARACTERIZATION OF THIOBUTYLTRIPHENYLPHOSPHONIUM BROMIDE, A NOVEL THIOL REAGENT TARGETED TO THE MITOCHONDRIAL MATRIX, Archives of biochemistry and biophysics, 322(1), 1995, pp. 60-68
Mitochondria are continually exposed to oxidative stress due to supero
xide formation by the respiratory chain which increases in pathologica
l situations such as ischemia reperfusion and neurodegeneration. Durin
g oxidative stress there are a number of changes in mitochondrial low-
molecular-weight and protein thiols. In particular, the mitochondrial
glutathione pool becomes oxidized and forms mixed disulfides with prot
ein thiols. To investigate changes in the redox state and conjugation
of mitochondrial glutathione, and other mitochondrial thiols, we desig
ned and characterized a thiol probe specifically targeted to the mitoc
hondrial matrix. This molecule, thiobutyltriphenyl-phosphonium bromide
, contains a thiol group linked to a lipophilic triphenylphosphonium c
ation which causes it to accumulate in the negatively charged mitochon
drial matrix. Using [C-14] thiobutyltriphenylphosphonium bromide we co
nfirmed that it was selectively accumulated by isolated mitochondria.
In the mitochondrial matrix the thiol group equilibrated with endogeno
us thiols and during oxidative stress became disulfide-bonded to prote
in and nonprotein thiols. Therefore, this novel thiol probe can be use
d to label protein thiol groups and to investigate changes in conjugat
ion and redox state of mitochondrial thiols during oxdative stress. (C
) 1995 Academic Press, Inc.