Goldberg E M, Borchardt D B, Zidovetzki R
Department of Biology, University of California, Riverside, USA.
Eur J Biochem. 1998 Dec 1;258(2):722-8. doi: 10.1046/j.1432-1327.1998.2580722.x.
The effects of the PKC substrate histone 1 and the PKC activator diolein (Ole2Gro) on the structure of phosphatidylcholine (PtdCho)/phosphatidylserine (PtdSer), or PtdCho/phosphatidylglycerol (PtdGro) bilayers were studied using 2H-NMR. The results showed that in PtdCho/PtdSer bilayers, histone preferentially increased order parameters of the acyl chains of the PtdSer, but not the PtdCho lipid component. This effect was additive with the effect of Ole2Gro, which equally increased the ordering of the acyl chains of both PtdCho and PtdSer. The histone-induced change in the conformation of the PtdCho headgroups in PtdCho/PtdSer bilayers indicated that positively charged residues of the bound histone are located above the lipid-water interface and their location was altered by the presence of Ole2Gro. A different picture was observed in the case of PtdCho/PtdGro bilayers; although the effect of Ole2Gro on both the PtdCho or the PtdGro components was similar to the case of the PtdCho/PtdSer bilayers, histone did not significantly affect the order parameters of PtdCho or PtdGro in either the absence or presence of Ole2Gro. The results indicate that histone 1 induces clustering of PtdSer in PtdCho bilayers which may contribute to PKC activation. Moreover, the observed differences in the interactions of histone with PtdCho/PtdSer compared with PtdCho/PtdGro bilayers may explain the higher efficiency of PtdSer in activating PKC.
利用2H-核磁共振研究了蛋白激酶C（PKC）底物组蛋白1和PKC激活剂二油精（Ole2Gro）对磷脂酰胆碱（PtdCho）/磷脂酰丝氨酸（PtdSer）或PtdCho/磷脂酰甘油（PtdGro）双层膜结构的影响。结果表明，在PtdCho/PtdSer双层膜中，组蛋白优先增加PtdSer酰基链的序参数，但不影响PtdCho脂质成分的序参数。这种效应与Ole2Gro的效应相加，Ole2Gro同样增加了PtdCho和PtdSer酰基链的有序性。组蛋白诱导的PtdCho/PtdSer双层膜中PtdCho头部基团构象的变化表明，结合的组蛋白的带正电残基位于脂质-水界面上方，并且它们的位置因Ole2Gro的存在而改变。在PtdCho/PtdGro双层膜的情况下观察到了不同的情况；尽管Ole2Gro对PtdCho或PtdGro成分的影响与PtdCho/PtdSer双层膜的情况相似，但在不存在或存在Ole2Gro的情况下，组蛋白均未显著影响PtdCho或PtdGro的序参数。结果表明，组蛋白1诱导PtdCho双层膜中PtdSer聚集，这可能有助于PKC激活。此外，与PtdCho/PtdGro双层膜相比，观察到的组蛋白与PtdCho/PtdSer相互作用的差异可能解释了PtdSer激活PKC的更高效率。
