Implication of SH‐groups in the mitochondrial energy‐coupling system revealed by measurements of ¹⁴C‐ethacrynate incorporation into rat liver mitochondria

ADP‐ and oligomycin‐sensitive redox behavior of F0 b thiol in ATPsynthase depends on neighbored primary structure: Investigations using 14‐C‐labeled alpha lipoic acid

“…In accord with the findings cited above [18,58] are observations on accessibility of F 0 subunits from the cytoplasmic side of the mitochondrial membrane [14,44]. Other work has confirmed such accessibility using different types of thiol group reagents or blockers.…”

“…This implies, that oligomycin-sensitive thiol groups are localized outside the carrier region and were early associated with the coupling mechanism [18]. Oligomycin specifically suppressed the release of thiol groups by ADP [18]. In the highly purified mitochondrial ATPsynthase the release of oligomycin-sensitive thiol groups by ADP can be deduced to F 0 b subunit, (see present paper), indicating a long range conformational change between F 1 and F 0 b (β-b conformational change).…”

“…As is becoming evident from the foregoing discussion, in mitochondria, oligomycin -sensitive thiol reactivity occurs to a remarkable extent [1,4,7,8,[18][19][20]33,43,57,58,61,62,64,66]. Such mitochondrial -SH reactivity can be also deduced to working rat hearts in experimentation with MPG [65] and alpha lipoic acid [67].…”

“…Specifically ADP, when bound to AdN-translocase in whole mitochondria and to F 1 in ATPsynthase induces an increase of oligomycin insensitive as well as oligomycin-sensitive thiol groups [18,31,58]. Mitochondrial anion carriers are insensitive towards oligomycin [32,40] and accumulate added anions in the presence of respiratory inhibitors and oligomycin [40].…”

“…In order to avoid ATP breakdown during analysis, anion carriers have been investigated in presence of oligomycin [53]. This implies, that oligomycin-sensitive thiol groups are localized outside the carrier region and were early associated with the coupling mechanism [18]. Oligomycin specifically suppressed the release of thiol groups by ADP [18].…”