Calcium-Lipid Interactions Observed with Isotope-Edited Infrared Spectroscopy
Calcium-Lipid Interactions Observed with Isotope-Edited Infrared Spectroscopy
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用同位素编辑红外光谱观察钙-脂质相互作用
DOI：
10.1016/j.bpj.2020.04.013
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发表时间：
2020
影响因子：
3.4
通讯作者：
Baiz, Carlos R.
中科院分区：
文献类型：
--
作者：
Valentine, Mason L.;Cardenas, Alfredo E.;Elber, Ron;Baiz, Carlos R.
钙离子结合到含有阴离子脂质的脂质膜;然而，表征多组分膜中的特定离子-脂质相互作用仍然具有挑战性，因为它需要非微扰的脂质特异性探针。在这里，使用同位素编辑的红外光谱和分子动力学模拟的组合，我们表征的影响，生理相关的（2 mM）的Ca 2+浓度对两性离子磷脂酰胆碱和阴离子磷脂酰丝氨酸脂质混合脂质膜。我们发现，Ca 2+改变水和脂质头基之间的氢键形成一个涉及的脂质头基和水的配位复合物。这些相互作用扭曲界面水的取向，并防止与脂酯羰基的氢键。我们证明，实验，这些影响是更明显的阴离子磷脂酰丝氨酸脂质比两性离子磷脂酰胆碱脂质在同一膜。
Calcium ions bind to lipid membranes containing anionic lipids; however, characterizing the specific ion-lipid interactions in multicomponent membranes has remained challenging because it requires nonperturbative lipid-specific probes. Here, using a combination of isotope-edited infrared spectroscopy and molecular dynamics simulations, we characterize the effects of a physiologically relevant (2 mM) Ca2+concentration on zwitterionic phosphatidylcholine and anionic phosphatidylserine lipids in mixed lipid membranes. We show that Ca2+alters hydrogen bonding between water and lipid headgroups by forming a coordination complex involving the lipid headgroups and water. These interactions distort interfacial water orientations and prevent hydrogen bonding with lipid ester carbonyls. We demonstrate, experimentally, that these effects are more pronounced for the anionic phosphatidylserine lipids than for zwitterionic phosphatidylcholine lipids in the same membrane.