Reply to: Is the debate over grana stacking formation finally solved?
Reply to: Is the debate over grana stacking formation finally solved?
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DOI：
10.1038/s41477-021-00881-6
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发表时间：
2021-03
期刊：
影响因子：
18
通讯作者：
F. Müh;B. van Oort;Sujith Puthiyaveetil;H. Kirchhoff
中科院分区：
文献类型：
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作者：
F. Müh;B. van Oort;Sujith Puthiyaveetil;H. Kirchhoff
自然植物产生的物质基质。因此，我们可以对每个LHCII-三聚体少计数一个负电荷。以这种方式，我们重新评估了基粒托管的多亚基复合物的基质侧的净电荷（参见补充表1）。请注意，这种重新评估并不是详尽无遗的，因为并非所有的复合体都可以模拟。尽管如此，这些数据给出了由于蛋白质结合基团的pKa位移而导致的表面电荷密度大小降低的初步估计。这种效应确实很显著：表面电荷密度从SPS（无磷酸化）的σ=− 0.0389 cm− 2变为非标准质子化状态的σ=− 0.0259 cm− 2（补充表2）。我们使用精确的数值算法重新计算了静电斥力Fel（详见补充信息），类囊体膜之间穿过基质间隙的净力由F= FvdW+ Fel+Fhydro给出，其中水力结构力根据Fhydro= 1010 e − d/0.193 Nm− 2计算，如前4。图1显示了基质间隙中200 mM KCl和5 mM MgCl 2下的净力随膜分离距离的变化。值得注意的是，即使具有较小的Hamaker系数，也可以在没有蛋白质磷酸化的情况下为原始表面电荷密度实现力平衡（零交叉）4（图1a），
MATTERS ARISING NATURE PLANTS the stroma. As a consequence, we can count one negative charge less per LHCII-trimer. In this way, we re-evaluated the net charges on the stromal side of grana-hosted, multi-subunit complexes (see Supplementary Table 1). Note that this re-evaluation is not exhaustive, since not all complexes could yet be simulated. Nonetheless, the data give a first estimate of the decrease in the magnitude of the surface charge density due to pKa shifts of protein-bound groups. The effect is indeed significant: the surface charge density is changed from σ=− 0.0389 cm− 2 in the SPS (no phosphorylation) to σ=− 0.0259 cm− 2 for the non-standard protonation states (Supplementary Table 2). We recalculated the repulsive electrostatic force Fel using a refined numerical algorithm (see Supplementary Information for details).The net force between the thylakoid membranes across the stromal gap is given by F= FvdW+ Fel+Fhydro, where the hydrostructural force is calculated according to Fhydro= 1010e− d/0.193 Nm− 2, as before 4. Figure 1 shows the net force at 200 mM KCl and 5 mM MgCl2 in the stromal gap as a function of the membrane separation distance. It is noteworthy that even with the smaller Hamaker coefficients, force balance (zero crossing) can be achieved for the original surface charge density without protein phosphorylation 4 (Fig. 1a),