排序方式: 共有6条查询结果,搜索用时 15 毫秒
1
1.
Behavior of lysozyme adsorbed onto biological liquid crystal lipid monolayer at the air/water interface
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The interaction between proteins and lipids is one of the basic problems of modern biochemistry and biophysics.The purpose of this study is to compare the penetration degree of lysozyme into 1,2-diapalmitoyl-sn-glycero-3-phosphocholine(DPPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphoethano-lamine(DPPE) by analyzing the data of surface pressure–area(π–A) isotherms and surface pressure–time(π–T) curves.Lysozyme can penetrate into both DPPC and DPPE monolayers because of the increase of surface pressure at an initial pressure of 15 m N/m.However,the changes of DPPE are larger than DPPC,indicating stronger interaction of lysozyme with DPPE than DPPC.The reason may be due to the different head groups and phase state of DPPC and DPPE monolayers at the surface pressure of 15 m N/m.Atomic force microscopy reveals that lysozyme was absorbed by DPPC and DPPE monolayers,which leads to self-aggregation and self-assembly,forming irregular multimers and conical multimeric.Through analysis,we think that the process of polymer formation is similar to the aggregation mechanism of amyloid fibers. 相似文献
2.
Analysis of the induction of the myelin basic protein binding to the plasma membrane phospholipid monolayer
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Myelin basic protein(MBP) is an essential structure involved in the generation of central nervous system(CNS)myelin.Myelin shape has been described as liquid crystal structure of biological membrane.The interactions of MBP with monolayers of different lipid compositions are responsible for the multi-lamellar structure and stability of myelin.In this paper,we have designed MBP-incorporated model lipid monolayers and studied the phase behavior of MBP adsorbed on the plasma membrane at the air/water interface by thermodynamic method and atomic force microscopy(AFM).By analyzing the pressure–area(π–A) and pressure–time(π–T) isotherms,univariate linear regression equation was obtained.In addition,the elastic modulus,surface pressure increase,maximal insertion pressure,and synergy factor of monolayers were detected.These parameters can be used to modulate the monolayers binding of protein,and the results show that MBP has the strongest affinity for 1,2-dipalmitoyl-sn-glycero-3-phosphoserine(DPPS) monolayer,followed by DPPC/DPPS mixed and1,2-dipalmitoyl-sn-glycero-3-phospho-choline(DPPC) monolayers via electrostatic and hydrophobic interactions.AFM images of DPPS and DPPC/DPPS mixed monolayers in the presence of MBP(5 n M) show a phase separation texture at the surface pressure of 20 m N/m and the incorporation of MBP put into the DPPC monolayers has exerted a significant effect on the domain structure.MBP is not an integral membrane protein but,due to its positive charge,interacts with the lipid head groups and stabilizes the membranes.The interaction between MBP and phospholipid membrane to determine the nervous system of the disease has a good biophysical significance and medical value. 相似文献
3.
4.
5.
6.
Influence of amphotericin B on liquid crystal state of the Cholesterol/Dipalmitoylphosphatidylcholine monolayer in the presence of different metal cations
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Amphotericin B is a very effective antifungal drug,but it has an adverse reaction to the membrane of mammals' cells.The interaction between Am B and cholesterol(Chol) causes the formation of pores on the membrane to destroy its integrity.In particular,Am B has a significant effect on the permeability of membrane for K~+ions.It has been reported that Na+ions and Ca~(2+)ions may have some influence on the interaction between amphotericin B and lipid molecules.In this work,the effects of these metal cations on the physical state and intermolecular interaction of the Cholesterol/Dipalmitoylphosphatidylcholine(Chol/DPPC) monolayer with and without Am B have been investigated.The addition of Am B induces the change of physical state of the lipid monolayer from liquid-gel phase to liquid phase.Different metal cations could influence the phase transition of the Am B-lipid monolayer.The K~+ions and Ca2+ions make the obvious phase transition disappear.However,the presence of Na+ions has little influence on the phase transition of the Am B-lipid monolayer.The addition of Am B and the presence of different metal cations weaken the attractive force on the monolayers.After addition of Am B,the force between the molecules is the strongest in the environment of K+ions,thus is the weakest in the environment of Ca~(2+)ions,which may be due to the distribution of these metal cations inside and outside of cells.A large number of K+ions distribute inside of the cells,thus most of Na+and Ca~(2+)ions exist out of the cells.Hence,it may be possible that when Am B molecules are out of the cells,the reaction between the drug and lipid molecules is weaker than that inside the cells.These results may have a great reference value for further studying the toxicity mechanism of Am B and the influence of metal cations on the membrane. 相似文献
1