Study On The Immobilization Of Hemoglobin And Albumin By Nano Mesoporous MCFs

The research of protein immobilization methods and materials is a frontier subject in the field of modern bioengineering.Protein immobilization helps to protect the natural conformation and catalytic activity of proteins.Immobilized proteins can be widely used in biomedical,medical diagnosis and environmental science.However,there are still some problems to be solved for immobilized proteins,such as the selection of carrier materials suitable for human characteristics,the pore size of the material,channel adaptation,and the continuity of protein catalysis.The purpose of this paper is to control the pore size and surface functional groups of mesoporous materials,and proteins were successfully stabilized in the channels of mesoporous materials.The prepared host-guest nanocomposites showed high stability and catalytic activity.It can be used as an excellent carrier of protein and lay a foundation for the construction of efficient nanobioreactor.Mesoporous molecular sieve MCFs was successfully synthesized by hydrothermal method.This thesis is a study on proteinimmobilization in mesoporous molecular sieve.In this study,albumin from chicken egg white was successfully assembled into mesoporous molecular sieve MCFs.The amount of adsorbed protein was 71.08 mg/g.The powder X-ray diffraction and infraned spectra analysis showed that crystallinity of the composites was retained fine and the basic frameworks of the molecular sieves have not been destroyed by introduction of the enzyme.Thescanning electron microscopy andtransmission electron microscopy results showed that albumin from chicken egg white had been located in the channels of the molecular sieve.The composite materials have good stability.The average particle diameter of MCFs was 2200±50 nm.The average particle diameter of the hybrid materials was 2250±50 nm.Differential thermal analysis-Thermal gravimetric result indicated that the hybrid materials have good thermal stability.Fluorescence spectroscopic studies showed that after the protein was adsorbed its structure and conformation was not changed and fixed fluorescence phenomena appear.The adsorption of proteins on MCFs has been studied.It was demonstrated that the three-dimensional porous structure of MCFs molecular sieves has a higheralbumin loading.The bovine hemoglobin was successfully immobilized into the mesoporous molecular sieve MCFs,and the immobilized enzyme was 50.27 mg/g.By optimizing the adsorption conditions of hemoglobin on MCFs,the desirable adsorbate/adsorbent（Hb）（MCFs）（mass ratio,m/m）for 3/50 was achieved.A series of characterization results indicated thathemoglobin had been successfully immobilized in the main channels of the material.The effects of the modified MCFs on the pore size and pore-size distribution of have been discussed.The scanning electron microscopic results showed that the average particle diameter of MCFs-Hb was 2212±50 nm.The average particle diameter of（CH₃-MCFs）-Hb was 2219±50 nm.The adsorption process of MCFs/（CH₃-MCFs）adsorbing hemoglobin was fitted with pseudo-second-order kineticequation.The process of MCFs/（CH₃-MCFs）adsorbing hemoglobin enzyme belonged to an exothermic reaction and belonged to a spontaneous reaction.Due to the extremely high specific surface area of the methylated MCFs,the interaction between surface functional groups and proteins can be effectively improved,and the repulsive electrostatic interactions between adsorbed proteins can be minimized because the surface charge of the modified molecular sieve is close to the isoelectric point（PI）of the proteins.Therefore,after the adsorption of methylated modified MCFs,the enzyme activity was increased by about 50%.During the depsorption process of composite MCFs-Hb/（CH₃-MCFs）-Hb in 0.1 mol/L Na OH solution,at 5 h an equilibrium was reached and the desorption rates were 72.58%and 69.67%,respectively.The results of reusing activity showed that the times of repeated use of methylated mesoporous materials（CH₃-MCFs）-Hb were higher than that of MCFs-Hb,indicating that the"leakage"of enzyme in the main material was reduced after MCFs methylation.The luminescence spectra show that the prepared composites have some light emission properties.