Souzu H
Biochim Biophys Acta. 1986 Oct 9;861(2):361-7. doi: 10.1016/0005-2736(86)90439-6.
The effects of polyamines, spermine, spermidine and putrescine on the stabilization of the membrane organization of Escherichia coli cells were studied using measurements of fluorescence polarization change of extrinsic fluorescence probes in membrane specimens as a function of temperature. The effects of the polyamines on the restoration of the cell viability after freeze-thawing were also investigated. In logarithmic-phase membrane specimens, polyamines depressed the polarization ratio increase below the transition temperatures in a dose-dependent manner. The physiologically relevant concentration of polyamines repressed the ratios to the same levels as are obtained with the stationary-phase specimens. In the stationary-phase specimens, no effect of polyamines on repression of the polarization increase was observed. A preliminary exposure of logarithmic-phase cells to polyamines protected the cells from the reduction of viability in freeze-thawing. However, a considerably high concentration and a certain length of preincubation time were required in order to an effect to be exerted. These results indicate that the intracellular polyamines could stabilize the membrane organization of logarithmic-phase cells to the same extent as in the stationary-phase cell membranes. It is conjectured that the membrane stability which is mediated by the polyamines results in cellular resistance to freeze-thawing, as it is attained by increasing the growth phase of the cells.
利用膜标本中外源荧光探针的荧光偏振变化随温度的测量，研究了多胺、精胺、亚精胺和腐胺对大肠杆菌细胞膜组织稳定性的影响。还研究了多胺对冻融后细胞活力恢复的影响。在对数生长期的膜标本中，多胺以剂量依赖的方式抑制低于转变温度时偏振比的增加。生理相关浓度的多胺将偏振比抑制到与稳定期标本相同的水平。在稳定期标本中，未观察到多胺对抑制偏振增加有影响。对数生长期细胞预先暴露于多胺可保护细胞免受冻融过程中活力降低的影响。然而，为了发挥作用，需要相当高的浓度和一定的预孵育时间。这些结果表明，细胞内多胺可以将对数生长期细胞的膜组织稳定到与稳定期细胞膜相同的程度。据推测，由多胺介导的膜稳定性导致细胞对冻融的抗性，因为它是通过增加细胞的生长阶段来实现的。
