van Meer G, Op den Kamp J A
J Cell Biochem. 1982;19(2):193-204. doi: 10.1002/jcb.240190209.
Phosphatidylcholine specific phospholipid exchange protein was used to introduce (14C)-labeled phosphatidylcholine of different fatty acyl compositions into the intact human erythrocyte. Hydrolysis by a combination of phospholipase A2 and sphingomyelinase was applied to prove that originally all newly introduced phosphatidylcholine resided in the outer monolayer. Subsequently the erythrocytes were reincubated at 37 degrees C, and redistribution of the introduced (14C)phosphatidylcholine was monitored by applying the combination of phospholipases after different times of incubation. In the situation where 20% of the native erythrocyte phosphatidylcholine had been replaced by phosphatidylcholine from (14C)choline-labeled rat liver microsomal membranes, a slow translocation of the (14C)microsomal phosphatidylcholine was found, with a half-time of transbilayer equilibration of 10.8 hr. Furthermore, the transbilayer movement of probe amounts of (14C)dipalmitoyl-phosphatidylcholine, (14C)egg phosphatidylcholine and (14C)soybean phosphatidylcholine was studied under conditions whereby the fatty acyl composition of the bulk erythrocyte phosphatidylcholine remained unchanged. In correlation to the increasing unsaturation of the probe, half-times for the transbilayer equilibration were calculated to be 26.9, 12.8, and 8.1 hr, respectively.
使用磷脂酰胆碱特异性磷脂交换蛋白将不同脂肪酰基组成的（14C）标记磷脂酰胆碱引入完整的人红细胞。通过磷脂酶A2和鞘磷脂酶的联合作用进行水解，以证明最初所有新引入的磷脂酰胆碱都位于外单层。随后将红细胞在37℃下再孵育，并在不同孵育时间后通过应用磷脂酶组合来监测引入的（14C）磷脂酰胆碱的重新分布。在20%的天然红细胞磷脂酰胆碱被来自（14C）胆碱标记的大鼠肝微粒体膜的磷脂酰胆碱取代的情况下，发现（14C）微粒体磷脂酰胆碱有缓慢的转位，跨膜平衡的半衰期为10.8小时。此外，在大量红细胞磷脂酰胆碱的脂肪酰基组成保持不变的条件下，研究了探针量的（14C）二棕榈酰磷脂酰胆碱、（14C）鸡蛋磷脂酰胆碱和（14C）大豆磷脂酰胆碱的跨膜运动。与探针不饱和程度的增加相关，跨膜平衡的半衰期分别计算为26.9、12.8和8.1小时。
