Bakás L S, Disalvo E A
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Argentina.
Cryobiology. 1991 Jun;28(3):279-87. doi: 10.1016/0011-2240(91)90033-k.
The stability of unilamellar vesicles during freeze-thaw cycles strongly depends on the Ca2+ concentration in the aqueous solution. Experiments performed at equal ionic strengths with Na+ and Ca2+ solutions indicate that the effect observed is specific for Ca2+. This is interpreted to be a consequence of the adsorption of Ca2+ on the vesicle bilayers. The variation of lipid and Ca2+ concentrations indicates that stability is achieved at a particular Ca2+/lipid ratio of 8 mol/mol above which vesicles are stable. The stability appears to be mainly conferred by the external Ca2+ in both slow and rapid cycles, independent of the ionic vesicle content. However, internal Ca2+ seems to increase the stability according to the F/T cycle rate to some extent in the absence of Ca2+ in the external solution.
单层囊泡在冻融循环过程中的稳定性很大程度上取决于水溶液中的Ca2+浓度。在具有相同离子强度的Na+和Ca2+溶液中进行的实验表明，观察到的效应是Ca2+特有的。这被解释为Ca2+吸附在囊泡双层膜上的结果。脂质和Ca2+浓度的变化表明，在特定的Ca2+/脂质比为8 mol/mol时可实现稳定性，高于该比例囊泡是稳定的。在缓慢和快速循环中，稳定性似乎主要由外部Ca2+赋予，与离子囊泡含量无关。然而，在外部溶液中不存在Ca2+的情况下，内部Ca2+似乎在一定程度上根据冻融循环速率增加稳定性。
