Szabó I, Báthori G, Wolff D, Starc T, Cola C, Zoratti M
Centro CNR Fisiologia Mitocondri, Dip. Scienze Biomediche Sperimentali, Padua, Italy.
Biochim Biophys Acta. 1995 Apr 12;1235(1):115-25. doi: 10.1016/0005-2736(94)00306-a.
Patch-clamp and planar bilayer experiments on porin-less yeast mitochondria have allowed the characterization of a cationic channel activated at matrix-side positive (unphysiological) potentials. In voltage-pulse experiments, inactivation was a faster process than activation and the time constant for inactivation was more steeply dependent on voltage than the one for activation. The channel exhibited various conductance states whose occupancy depended on the applied transmembrane potential. In bilayer experiments, the presence of the pCOx-IV leader peptide induced fast gating in a voltage-dependent manner. A comparison with previously described activities suggests that the pore may coincide with the peptide-sensitive channel (PSC) (Thieffry et al. (1988) EMBO J. 7, 1449-1454) as well as with two other activities (Dihanich et al. (1989) Eur. J. Biochem. 181, 703-708; Tedeschi et al. (1987) J. Membr. Biol. 97, 21-29) assigned to the mitochondrial outer membrane. The possible relationship of this channel to the mitochondrial megachannel is discussed.
对无孔蛋白酵母线粒体进行的膜片钳和平面双层实验，已实现对一种在基质侧为正（非生理）电位时被激活的阳离子通道的特性描述。在电压脉冲实验中，失活是比激活更快的过程，且失活的时间常数比激活的时间常数更强烈地依赖于电压。该通道呈现出多种电导状态，其占据情况取决于所施加的跨膜电位。在双层实验中，细胞色素氧化酶IV前导肽的存在以电压依赖的方式诱导快速门控。与先前描述的活性进行比较表明，该孔道可能与肽敏感通道（PSC）（蒂弗里等人，（1988年）《欧洲分子生物学组织杂志》7卷，1449 - 1454页）以及另外两种活性（迪哈尼奇等人，（1989年）《欧洲生物化学杂志》181卷，703 - 708页；泰德eschi等人，（1987年）《膜生物学杂志》97卷，21 - 29页）一致，这两种活性被归因于线粒体外膜。讨论了该通道与线粒体大通道的可能关系。
