Surface and interfacial behavior of protein molecules are crucial for the protein function involved in many biochemical processes and biomedical products such as enzyme design,bio-separation,drug design and delivery.T...Surface and interfacial behavior of protein molecules are crucial for the protein function involved in many biochemical processes and biomedical products such as enzyme design,bio-separation,drug design and delivery.This article is devoted to an overview of design and regulation of the surface and interfacial behavior of protein molecules.The improvement of enzyme surface such as the directed evolution and the rational design of enzymes is introduced at first,followed by the rational design of protein interface for the protein assembly.Thereafter,the design of micro-environment and ligands are described as two examples for the design guided by protein surface.Then the design of protein surface and interface with the help of artificial intelligence will be discussed.展开更多
In our previous work, a series of polyethylenimine(PEI)-derived cation exchangers were synthesized using PEIgrafted resin FF-PEI-L740(ionic capacity, 740 mmol·L^-1) as the basic resin to study lysozyme adsorption...In our previous work, a series of polyethylenimine(PEI)-derived cation exchangers were synthesized using PEIgrafted resin FF-PEI-L740(ionic capacity, 740 mmol·L^-1) as the basic resin to study lysozyme adsorption and chromatographic behavior. It was found that the resin with an ionic capacity of 630 mmol·L^-1(FF-PEI-CR630)possessed high adsorption performance towards lysozyme at 0–100 mmol·L^-1 Na Cl. Therefore, in this work,FF-PEI-CR630 was selected to study the influences of pH and ionic strength(IS) on protein adsorption and chromatographic behavior towards lysozyme. The increase of lysozyme adsorption capacity in the pH range of 6 to 10 was observed. However, the uptake rate decreased in the pH range of 6 to 8 and then remained essentially unchanged from pH 8 to pH 10. Increasing IS led to decreased protein adsorption capacity and increased uptake rate in different pH ranges. Besides, FF-PEI-CR630 maintained dynamic binding capacity as high as over150 mg·ml^-1 at pH 8–10 without NaCl. The research has thus provided insight into the selection of proper pH and IS conditions for protein purification by using FF-PEI-CR630.展开更多
在有 L 半胱氨酸的帮助的水的答案的银 nanoparticles (Ag NP ) 的绿、控制尺寸的合成被介绍。Ag NP 的尺寸随 L 半胱氨酸集中的增加减少，并且能被调整 L 半胱氨酸集中因此控制。有一般水准的 Ag NP 3 nm 缩放的 TEM 分析表演能面对 1....在有 L 半胱氨酸的帮助的水的答案的银 nanoparticles (Ag NP ) 的绿、控制尺寸的合成被介绍。Ag NP 的尺寸随 L 半胱氨酸集中的增加减少，并且能被调整 L 半胱氨酸集中因此控制。有一般水准的 Ag NP 3 nm 缩放的 TEM 分析表演能面对 1.0 mmol/L L 半胱氨酸被生产， Ag NP 的大约 1:6 种尺寸当 L 半胱氨酸(17 nm ) 不在时获得了。assynthesized 银胶体的答案是稳定的并且没有任何降水，能在房间温度被存储为至少二个月。这 L 半胱氨酸帮助了方法简单、可行、有效，并且将便于 Ag NP 的生产和申请。展开更多
Our previous studies have reported the presence of "chain delivery" effects of protein adsorption onto ion exchangers with polymer-grafted ion-exchange groups, such as dextran-grafted and poly(ethylenimine)-...Our previous studies have reported the presence of "chain delivery" effects of protein adsorption onto ion exchangers with polymer-grafted ion-exchange groups, such as dextran-grafted and poly(ethylenimine)-modified Sepharose gels. However, it is unclear if the "chain delivery" occurs on affinity adsorption with specific interactions. This work is designed to address this issue. A dextran-grafted Sepharose gel was prepared, and then the matrix was modified using diethylaminoethyl, a typical ion-exchange group, or octapeptide(FYCHWQDE), an affinity ligand for human immunoglobulin G(h Ig G) to prepare ion-exchange or affinity adsorbents, respectively.Results of h Ig G adsorption showed that the uptake rate represented by the effective diffusivity of h Ig G onto the dextran-grafted ion exchangers was obviously enhanced by the dextran grafting, indicating the presence of"chain delivery" of the bound proteins on the charged groups on the dextran chains. By contrast, the effective diffusivity of h Ig G changed little as ligand density increased on the dextran-grafted FYCHWQDE adsorbents.Their adsorption capacities decreased and effective diffusivities were not accelerated by the dextran grafting.Thus, this work clarified that grafted dextran could not accelerate h Ig G uptake rate on the affinity resins, or in other words, chain delivery did not occur on the specific interaction-based affinity adsorption.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21978205 and 91534119)The National Key Research and Development Program of China(No.2018YFA0900700)the Innovation Foundation of Tianjin University。
文摘Surface and interfacial behavior of protein molecules are crucial for the protein function involved in many biochemical processes and biomedical products such as enzyme design,bio-separation,drug design and delivery.This article is devoted to an overview of design and regulation of the surface and interfacial behavior of protein molecules.The improvement of enzyme surface such as the directed evolution and the rational design of enzymes is introduced at first,followed by the rational design of protein interface for the protein assembly.Thereafter,the design of micro-environment and ligands are described as two examples for the design guided by protein surface.Then the design of protein surface and interface with the help of artificial intelligence will be discussed.
基金supported by the National Natural Science Foundation of China (Nos. 21878222 and 21621004).
文摘In our previous work, a series of polyethylenimine(PEI)-derived cation exchangers were synthesized using PEIgrafted resin FF-PEI-L740(ionic capacity, 740 mmol·L^-1) as the basic resin to study lysozyme adsorption and chromatographic behavior. It was found that the resin with an ionic capacity of 630 mmol·L^-1(FF-PEI-CR630)possessed high adsorption performance towards lysozyme at 0–100 mmol·L^-1 Na Cl. Therefore, in this work,FF-PEI-CR630 was selected to study the influences of pH and ionic strength(IS) on protein adsorption and chromatographic behavior towards lysozyme. The increase of lysozyme adsorption capacity in the pH range of 6 to 10 was observed. However, the uptake rate decreased in the pH range of 6 to 8 and then remained essentially unchanged from pH 8 to pH 10. Increasing IS led to decreased protein adsorption capacity and increased uptake rate in different pH ranges. Besides, FF-PEI-CR630 maintained dynamic binding capacity as high as over150 mg·ml^-1 at pH 8–10 without NaCl. The research has thus provided insight into the selection of proper pH and IS conditions for protein purification by using FF-PEI-CR630.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China （Grant No. 21236005）, the Natural Science Foundation of Tianjin （No. 13JCZDJC31100）, China Scholarship Council （CSC）, and the Innovation Foundation of Tianjin University.
文摘在有 L 半胱氨酸的帮助的水的答案的银 nanoparticles (Ag NP ) 的绿、控制尺寸的合成被介绍。Ag NP 的尺寸随 L 半胱氨酸集中的增加减少，并且能被调整 L 半胱氨酸集中因此控制。有一般水准的 Ag NP 3 nm 缩放的 TEM 分析表演能面对 1.0 mmol/L L 半胱氨酸被生产， Ag NP 的大约 1:6 种尺寸当 L 半胱氨酸(17 nm ) 不在时获得了。assynthesized 银胶体的答案是稳定的并且没有任何降水，能在房间温度被存储为至少二个月。这 L 半胱氨酸帮助了方法简单、可行、有效，并且将便于 Ag NP 的生产和申请。
基金Supported by the National Natural Science Foundation of China(21236005,21621004)
文摘Our previous studies have reported the presence of "chain delivery" effects of protein adsorption onto ion exchangers with polymer-grafted ion-exchange groups, such as dextran-grafted and poly(ethylenimine)-modified Sepharose gels. However, it is unclear if the "chain delivery" occurs on affinity adsorption with specific interactions. This work is designed to address this issue. A dextran-grafted Sepharose gel was prepared, and then the matrix was modified using diethylaminoethyl, a typical ion-exchange group, or octapeptide(FYCHWQDE), an affinity ligand for human immunoglobulin G(h Ig G) to prepare ion-exchange or affinity adsorbents, respectively.Results of h Ig G adsorption showed that the uptake rate represented by the effective diffusivity of h Ig G onto the dextran-grafted ion exchangers was obviously enhanced by the dextran grafting, indicating the presence of"chain delivery" of the bound proteins on the charged groups on the dextran chains. By contrast, the effective diffusivity of h Ig G changed little as ligand density increased on the dextran-grafted FYCHWQDE adsorbents.Their adsorption capacities decreased and effective diffusivities were not accelerated by the dextran grafting.Thus, this work clarified that grafted dextran could not accelerate h Ig G uptake rate on the affinity resins, or in other words, chain delivery did not occur on the specific interaction-based affinity adsorption.
