Unbiased, all-atom simulations of mixtures representative of the inner and outer leaflets of a mammalian red blood cell and a synaptic vesicle reveal many cholesterol flip-flop events over the 5 μsec duration of the simulations. Enough events are observed for a direct estimate of the flip-flop rate. Slower rates are found in more ordered membranes, and faster rates in more disordered membranes, consistent with earlier reports in the literature. However, the rates found here are neither as fast as the fastest nor as slow as the slowest rates obtained by previous simulations. The difference likely stems from the compositions studied here, which unlike previous work include exclusively lipids with differing acyl chains, as observed in mammalian lipidomes.

代表哺乳动物红细胞内外叶和突触小泡的混合物的无偏见全原子模拟揭示了 5 微秒模拟持续时间内的许多胆固醇翻转事件。观察到的事件足够多，可以直接估计触发率。在更有序的膜中发现更慢的速率，在更无序的膜中发现更快的速率，这与文献中的早期报道一致。然而，这里发现的速率既没有最快的速率那么快，也没有以前模拟获得的最慢速率那么慢。差异可能源于此处研究的成分，这与以前的工作不同，如在哺乳动物脂质组中观察到的那样，仅包括具有不同酰基链的脂质。