Theoretical and experimental studies of complex peptide-membrane systems: general discussion.
Theoretical and experimental studies of complex peptide-membrane systems: general discussion.
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复杂肽膜系统的理论和实验研究：一般讨论。
DOI：
10.1039/d1fd90066h
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发表时间：
2021
影响因子：
3.4
通讯作者：
Aguilar M
中科院分区：
文献类型：
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作者：
Aguilar M
Mibel Aguilar 对 Ronald J. Clarke 的论文进行了一般性讨论：您是否尝试过其他带负电的脂质来确定静电相互作用是否对 PS 具有特异性？另外，QCM 和 CD 实验的 P:L 比率是多少？您是否预计螺旋含量会比您观察到的要高？罗纳德·J·克拉克回答：是的，事实上我们确实研究了其他带负电的脂质。在我们的研究过程中，我们发现一种简单但非常有效的筛选静电相互作用的方法是测量含有 Na+、K+-ATP 酶的脂质囊泡或膜片段悬浮液的静态光散射。如果发生相互作用，胶体系统就会发生聚集和堵塞，最初导致光散射大幅增加。 1 在聚氨基酸浓度相对较高的情况下，光散射增加，随后散射衰减较慢，这可能是由于脂质膜的透化和破坏。为了进行这些测量，我们在实验室中重新调整了荧光计的用途，并测量了 826 nm 处入射光的 90 度散射，对应于仪器氙弧灯的高强度线。为了确定肽与膜的相互作用是否针对磷脂酰丝氨酸，我们使用由 85 mol% 二油酰磷脂酰胆碱 (DOPC) 和 15 mol% 二油酰磷脂酰丝氨酸 (DOPS)、二油酰磷脂酰甘油 (DOPG) 或二油酰磷脂酸 (DOPA) 组成的囊泡进行了光散射测量。添加聚-L-赖氨酸后，含有 DOPS、DOPG 或 DOPA 的囊泡均表现出类似的光散射大幅增加，表明赖氨酸与膜的静电相互作用并非 PS 所特有的。 2 赖氨酸也
Mibel Aguilar opened a general discussion of the paper by Ronald J. Clarke: Did you try other negatively charged lipids to determine if the electrostatic interaction was speci c for PS? Also, what was the P: L ratio for the QCM and CD experiments? Would you have expected the helical content to be higher than you observed?Ronald J. Clarke replied: Yes, in fact we did investigate other negatively charged lipids. In the course of our studies we found that a simple but very effective method to screen for electrostatic interactions is to measure the static light scattering of suspensions of lipid vesicles or membrane fragments containing the Na+, K+-ATPase. If an interaction occurs, aggregation and occulation of the colloidal system occurs, resulting initially in a large increase in light scattering. 1 At relatively high concentrations of polyamino acids, the light scattering increase is followed by a slower decay in scattering, probably due to permeabilisation and disruption of the lipid membrane. For these measurements we repurposed a uorimeter in our laboratory and measured the scattering at 90 to the incident light at 826 nm, corresponding to a high intensity line of the instrument’s xenon arc lamp. To determine whether the peptide interaction with the membrane is speci c to phosphatidylserine, we carried out light scattering measurements using vesicles composed of 85 mol% dioleoylphosphatidylcholine (DOPC) and 15 mol% of either dioleoylphosphatidylserine (DOPS), dioleoylphosphatidylglycerol (DOPG) or dioleoylphosphatidic acid (DOPA). Vesicles containing DOPS, DOPG or DOPA all showed similar large increases in light scattering a er the addition of poly-L-lysine, indicating that the electrostatic interaction of lysine with the membrane is not speci c to PS. 2 Lysine also