HYPERTHERMIA-INDUCED INHIBITION OF RESPIRATION AND MITOCHONDRIAL PROTEIN DENATURATION IN CHL CELLS
HYPERTHERMIA-INDUCED INHIBITION OF RESPIRATION AND MITOCHONDRIAL PROTEIN DENATURATION IN CHL CELLS
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DOI：
10.3109/02656738709140380
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发表时间：
1987-03-01
影响因子：
3.1
通讯作者：
KRUUV, J
中科院分区：
文献类型：
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作者：
LEPOCK, JR;CHENG, KH;KRUUV, J
通过O2消耗测定的中国仓鼠肺V79细胞的呼吸，当以Arrhenius方式作图时，从8 ℃到40 ℃线性增加，但在40 ℃以上被强烈抑制。分离自V79细胞的线粒体蛋白在28和40 ℃经历结构转变。这是由共轭芘马来酰亚胺的荧光激发光谱的变化，并在较小程度上，内在的蛋白质荧光团的支持。用克里思马来酰亚胺衍生物进行的电子自旋共振标记研究表明，广泛的蛋白质解折叠与40 ℃转变一致。在40 ℃的结构转变与O2消耗的抑制很好地相关，是不可逆的并且可能是由于蛋白质变性，而在28 ℃的变化是可逆的并且对O2消耗没有影响。先前的研究表明，在线粒体膜中存在从约8 ℃延伸至30 ℃的宽的脂质转变，所有脂质在30 ℃以上处于液晶态。因此，脂质转变的开始可诱导在28 ℃观察到的蛋白质构象变化，但在40 ℃以上呼吸的抑制可单独由蛋白质变性来解释。稳定蛋白质构象的28 - 40 ℃区域对应于V79细胞生长的温度范围。
Respiration of Chinese hamster lung V79 cells, as assayed by O2 consumption, increases linearly from 8 to 40.degree.C when plotted in the Arrhenius fashion but is strongly inhibited above 40.degree.C. The protein of mitochondria isolated from V79 cells undergoes structural transitions at 28 and 40.degree.C. This is supported by changes in the fluorscence excitation spectrum of conjugated pyrene maleimide and, to a lesser extent, intrinsic protein fluorophores. Electron spin resonance labelling studies with a derivative of tempo maleimide imply that extensive protein unfolding coincides with the 40.degree.C transition. The structural transition at 40.degree.C correlates well with inhibition of O2 consumption, is irreversible and is probably due to protein denaturation, while the change at 28.degree.C is reversible and has no effect on O2 consumption. Previous studies indicate the presence of a broad lipid transition extending from approximately 8 to 30.degree.C in mitochondrial membranes with all lipids being in the liquid-crystalline state above 30.degree.C. Thus, the onset of the lipid transition may induce the observed protein conformational change at 28.degree.C, but inhibition of respiration above 40.degree.C can be explained by protein denaturation alone. The region from 28 to 40.degree.C of stable protein conformation corresponds to the temperature range of V79 cell growth.