A Langmuir monolayer study of the action of phospholipase A2 on model phospholipid and mixed phospholipid-GM1 ganglioside membranes.
A Langmuir monolayer study of the action of phospholipase A2 on model phospholipid and mixed phospholipid-GM1 ganglioside membranes.
复制标题
磷脂酶 A2 对模型磷脂和混合磷脂-GM1 神经节苷脂膜作用的 Langmuir 单层研究
DOI：
10.1016/j.colsurfb.2013.12.032
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Rogalska
中科院分区：
文献类型：
--
作者：
Schulte;Krochowiec;Rogalska
偏振调制红外反射吸收光谱，表面压力测量和热力学分析被用来研究在空气/水界面的脂质单分子层的酶水解。需要Ca 2+的猪胰腺磷脂酶A2被用作催化剂。底物为纯的1，2-二月桂酰-sn-甘油-3-磷酸胆碱或混合的1，2-二月桂酰-sn-甘油-3-磷酸胆碱-单唾液酸四己糖神经节苷脂Langmuir膜。建立了单分子膜的物理化学性质，目的是与酶活性相关。在催化剂的推进下获得红外光谱;后者在受控的表面压力和膜面积下进行研究。两种脂质的不同红外信号特征的强度和频率的变化与由于水解的单层的性质的修改相关。允许检测吸附在界面处的酶的肽的酰胺I信号特性。热力学和红外结果表明，单唾液酸四己糖神经节苷脂增加膜中的脂质极性头的氢键。这种效应可能是混合膜中磷脂酶A2活性较低的原因，可用于开发抗酶脂质系统。
Polarization-modulation infrared reflection-absorption spectroscopy, surface pressure measurements and thermodynamic analysis were used to study enzymatic hydrolysis of lipid monolayers at the air/water interface. The Ca2+-requiring pork pancreatic phospholipase A2 was used as a catalyst. The substrates were pure 1,2-dilauroyl-sn-glycero-3-phosphocholine or mixed 1,2-dilauroyl-sn-glycero-3-phosphocholine – monosialotetrahexosylganglioside Langmuir films. The physicochemical properties of the monolayers were established with the aim of a correlation with enzyme activity.The infrared spectra were acquired upon the advancement of the catalysis; the latter was studied at a controlled surface pressure and area of the film. Changes of the intensity and frequency of different infrared signals characteristic for the two lipids were correlated with modification of the properties of the monolayer due to hydrolysis. The amide I signal characteristic for peptides permitted detecting the enzyme adsorbed at the interface. The thermodynamic and infrared results indicate that monosialotetrahexosylganglioside increases H-bonding of the lipid polar heads in the films. This effect, which may be responsible for the low activity of phospholipase A2 in the mixed films, could be used for developing enzyme-resistant lipid systems.