With frontal analysis (FA), the dependence of adsorption isotherms of insulin on the composition of mobile phase in reversed phase liquid chromatography (RPLC) has been investigated. This is also a good example to em...With frontal analysis (FA), the dependence of adsorption isotherms of insulin on the composition of mobile phase in reversed phase liquid chromatography (RPLC) has been investigated. This is also a good example to employ the stoichiometric displacement theory (SDT) for investigating solute adsorption in physical chemistry. Six kinds of mobile phase in RPLC were employed to study the effects on the elution curves and adsorption isotherms of insulin. The key points of this paper are: (1) The stability of insulin due to delay time after preparing, the organic solvent concentration, the kind and the concentration of ion pairing agent in mobile phase were found to affect both elution curve and adsorption isotherm very seriously. (2) To obtain a valid and comparable result, the composition of the mobile phase employed in FA must be as same as possible to that in usual RPLC of either analytical scale or preparative purpose. (3) Langmuir Equation and the SDT were employed to imitate these obtained adsorption isotherms. The expression for solute adsorption from solution of the SDT was found to have a better elucidation to the insulin adsorption from mobile phase in RPLC.展开更多
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-glycer...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.展开更多
文摘With frontal analysis (FA), the dependence of adsorption isotherms of insulin on the composition of mobile phase in reversed phase liquid chromatography (RPLC) has been investigated. This is also a good example to employ the stoichiometric displacement theory (SDT) for investigating solute adsorption in physical chemistry. Six kinds of mobile phase in RPLC were employed to study the effects on the elution curves and adsorption isotherms of insulin. The key points of this paper are: (1) The stability of insulin due to delay time after preparing, the organic solvent concentration, the kind and the concentration of ion pairing agent in mobile phase were found to affect both elution curve and adsorption isotherm very seriously. (2) To obtain a valid and comparable result, the composition of the mobile phase employed in FA must be as same as possible to that in usual RPLC of either analytical scale or preparative purpose. (3) Langmuir Equation and the SDT were employed to imitate these obtained adsorption isotherms. The expression for solute adsorption from solution of the SDT was found to have a better elucidation to the insulin adsorption from mobile phase in RPLC.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.21402114 and 11544009)the Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2016JM2010)+1 种基金the Fundamental Research Funds for the Central Universities of China(Grant No.GK201603026)the National University Science and Technology Innovation Project of China(Grant No.201610718013)
文摘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.
