FOURIER-TRANSFORM INFRARED SPECTROSCOPIC STUDIES OF THE EFFECT OF CALCIUM-IONS ON PHOSPHATIDYLSERINE
FOURIER-TRANSFORM INFRARED SPECTROSCOPIC STUDIES OF THE EFFECT OF CALCIUM-IONS ON PHOSPHATIDYLSERINE
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DOI：
10.1021/bi00295a043
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发表时间：
1983-01-01
期刊：
影响因子：
2.9
通讯作者：
MENDELSOHN, R
中科院分区：
文献类型：
--
作者：
DLUHY, RA;CAMERON, DG;MENDELSOHN, R
傅里叶变换红外光谱（FT-IR）研究了磷脂酰丝氨酸（PS）与Ca结合时发生的复杂构象变化。光谱证实了PS- ca2 +配合物中碳氢链的等温结晶。然而，与差示扫描量热法相比，差示扫描量热法检测不到100度以下的相变。在PS-Ca2+配合物中，几个FT-IR参数检测到30度-40度的结构变化。这些配合物中的C类似于在烷烃的固-固相变中观察到的。在PO2-带中观察到的位点对称分裂表明Ca2+作为双齿配体与PS磷酸结合；此外，Ca2+引起磷酸酯脱水。没有证据表明电离羧酸基团对Ca2+的特异性螯合或该基团的脱水；相反，羧酸盐在Ca2+存在下以固定化构象存在。界面区羰基简并振动的分裂表明Ca2+配合物中存在不同的旋转链异构体，以及与被困间隙水形成氢键的可能性。[这些研究在膜融合上有应用。]
Fourirer transform IR (FT-IR) spectroscopy is used to investigate the complex conformational changes that occur as phosphatidylserine (PS) binds to Ca. The spectra confirm the isothermal crystallization of the hydrocarbon chains in the PS-Ca2+ complex. However, in contrast to differential scanning calorimetry, which detects no phase transitions under 100.degree. C in PS-Ca2+ complexes, several FT-IR parameters detect structural changes at 30.degree.-40.degree. C in these complexes analogous to those observed in solid-solid phase transitions of alkanes. Site symmetry splitting observed in the PO2- bands suggests that Ca2+ binds to the PS phosphate as a bidentate ligand; in addition, Ca2+ causes a dehydration of the phosphate ester. No evidence is found for the specific chelation of Ca2+ by the ionized carboxylate group or the dehydration of this group; instead, the carboxylate exists in an immobilized conformation in the presence of Ca2+. Splitting of the degenerate vibrations of the carbonyl group at the interfacial region suggests different rotational chain isomers in the Ca2+ complex and the possibility of H-bonding with trapped interstitial water. [These studies have application to membrane fusion.].