Freisleben H J, Fuchs J, Mainka L, Zimmer G
Gustav-Embden-Zentrum der Biologischen Chemie, Universität Frankfurt, Federal Republic of Germany.
Arch Biochem Biophys. 1988 Oct;266(1):89-97. doi: 10.1016/0003-9861(88)90239-1.
Thiol reactivity was determined in rat heart mitochondria using chromophores of differing polarities: monobromobimane (MB), dithionitrobenzoate (NbS2), and bromobimane-q (MQ). The purpose of this study is to correlate reaction rates of protein thiols in the mitochondrial membrane with the oligomycin-inhibited and uncoupled states: In all cases investigated the reactivity of -SH groups toward MB decreases under the above conditions. In parallel with an increase of their uncoupling activities the uncouplers reduce the reaction rate of thiol groups toward NbS2 and, progressively, toward MQ, indicating differences in sensitivity of thiol groups to uncouplers depending on the polarity of the environment. The pattern of -SH reactivity under inhibition by oligomycin resembles that of carbonylcyanide-p-trifluoromethoxyphenylhydrazone. Functional changes of the mitochondrial membrane probably correlate with reactivity/polarity changes of membrane -SH groups. Masking of membrane thiol groups thus is not specific for uncouplers but is also observed under inhibition with oligomycin.
单溴代双硫腙（MB）、二硫代硝基苯甲酸（NbS2）和溴代双硫腙-q（MQ），测定大鼠心脏线粒体中的硫醇反应性。本研究的目的是将线粒体膜中蛋白质硫醇的反应速率与寡霉素抑制状态和解偶联状态相关联：在所有研究的情况下，-SH基团对MB的反应性在上述条件下均降低。随着解偶联剂解偶联活性的增加，它们会降低硫醇基团对NbS2的反应速率，并逐渐降低对MQ的反应速率，这表明硫醇基团对解偶联剂的敏感性因环境极性而异。寡霉素抑制下的-SH反应模式类似于羰基氰化物-对-三氟甲氧基苯腙。线粒体膜的功能变化可能与膜-SH基团的反应性/极性变化相关。因此，膜硫醇基团的掩盖并非解偶联剂所特有，在寡霉素抑制下也会观察到。
