fter the alcoholic group of serine located in the binding site of Anti-HumanIgM(Fcμ) (Rabbit IgG) was selectively activated by phenylmethylsulfonyl fluoride(PMSF) and displaced with hydrogen selenide(H2Se) , the seri...fter the alcoholic group of serine located in the binding site of Anti-HumanIgM(Fcμ) (Rabbit IgG) was selectively activated by phenylmethylsulfonyl fluoride(PMSF) and displaced with hydrogen selenide(H2Se) , the serine residue was con-verted to selenocysteine(SeCys). Because SeCys is a catalytic group of glutathioneperoxidase (GPX), the mutated antibody has the GPX activity which is seventytimes more than that of PZ51, the best GPX mimic in the world. Moreover, themutated antibody remains its original antibody titer.展开更多
The active center of human glutaredoxin(hGrx1)shares a common thioredoxin fold and specific affinity for substrate glutathione (GSH)with natural glutathione peroxidase(GPx).hGrx1 was redesigned to introduce the cataly...The active center of human glutaredoxin(hGrx1)shares a common thioredoxin fold and specific affinity for substrate glutathione (GSH)with natural glutathione peroxidase(GPx).hGrx1 was redesigned to introduce the catalytic selenocysteine residue to imi- tate the function of antioxidant selenoenzyme GPx in vivo.The human hGrx1 scaffold is a good candidate for potential medical application compared with other animal-originated protein scaffolds.Two consecutive rare codons(AGG-AGG)in the open reading frame of hGrx1 mRNA encoding Arg26-Arg27 residues can reduce seleno-hGrx1 expression level significantly in the Cys auxotrophic Escherichia coli strain BL21cysE51.Therefore,we optimized the rare codons,which resulted in a remarkable in- crease of the expression level in the Cys auxotrophic cells,which may be sufficient for future medical production.The engineered artificial selenoenzyme displays high GPx catalytic activity,rivaling that of some natural GPx proteins.Kinetic analysis of the engineered seleno-hGrx1 showed a typical ping-pong kinetic mechanism;its catalytic properties are similar to those of some nat- urally occurring GPx proteins.展开更多
Signal transduction across lipid bilayers is of profound importance in biological processes.In biological systems,natural enzymes mediate biochemical effects by binding to substrates and facilitating the conversion of...Signal transduction across lipid bilayers is of profound importance in biological processes.In biological systems,natural enzymes mediate biochemical effects by binding to substrates and facilitating the conversion of external signals into physiological responses.Sequential transmission of biological signals from one enzyme to the next promotes signal transduction with feedforward and feedback mechanisms.Reconstructing these processes in an artificial system provides potential applications and offers a new way to understand fundamental biological processes in depth.However,the design of artificial signal transduction systems regulated by artificial enzyme receptors in a predictable and intelligent manner remains a challenge.Herein,benefiting from the polarity-regulated characteristics of Se-containing compounds with artificial glutathione peroxidase(GPx)activity,we constructed an artificial transmembrane signaling receptor with a Se-containing GPx-like recognition head group,a membrane-anchoring group,and a pre-enzyme end group.The artificial supramolecular signal transduction system containing such signal transduction receptors extends the range of signaling systems based on enzyme regulation,which provides a new way to study natural signal processes in cells and artificially regulated biological processes.展开更多
文摘fter the alcoholic group of serine located in the binding site of Anti-HumanIgM(Fcμ) (Rabbit IgG) was selectively activated by phenylmethylsulfonyl fluoride(PMSF) and displaced with hydrogen selenide(H2Se) , the serine residue was con-verted to selenocysteine(SeCys). Because SeCys is a catalytic group of glutathioneperoxidase (GPX), the mutated antibody has the GPX activity which is seventytimes more than that of PZ51, the best GPX mimic in the world. Moreover, themutated antibody remains its original antibody titer.
基金supported by the National Natural Science Foundation of China(91027023,20874036,20921003,and 21004028)the Natural Science Foundation for the Youth(21004028)+2 种基金the Natural Science Foundation of China for Outstanding Younger Scientist(20725415)the 111 pro-ject(B06009)the National Basic Research Program(2007CB808006)
文摘The active center of human glutaredoxin(hGrx1)shares a common thioredoxin fold and specific affinity for substrate glutathione (GSH)with natural glutathione peroxidase(GPx).hGrx1 was redesigned to introduce the catalytic selenocysteine residue to imi- tate the function of antioxidant selenoenzyme GPx in vivo.The human hGrx1 scaffold is a good candidate for potential medical application compared with other animal-originated protein scaffolds.Two consecutive rare codons(AGG-AGG)in the open reading frame of hGrx1 mRNA encoding Arg26-Arg27 residues can reduce seleno-hGrx1 expression level significantly in the Cys auxotrophic Escherichia coli strain BL21cysE51.Therefore,we optimized the rare codons,which resulted in a remarkable in- crease of the expression level in the Cys auxotrophic cells,which may be sufficient for future medical production.The engineered artificial selenoenzyme displays high GPx catalytic activity,rivaling that of some natural GPx proteins.Kinetic analysis of the engineered seleno-hGrx1 showed a typical ping-pong kinetic mechanism;its catalytic properties are similar to those of some nat- urally occurring GPx proteins.
基金This work was supported by the National Key Research and Development Program of China(Nos.2020YFA0908500 and 2018YFA0901600)the National Natural Science Foundation of China(No.22161142015).
文摘Signal transduction across lipid bilayers is of profound importance in biological processes.In biological systems,natural enzymes mediate biochemical effects by binding to substrates and facilitating the conversion of external signals into physiological responses.Sequential transmission of biological signals from one enzyme to the next promotes signal transduction with feedforward and feedback mechanisms.Reconstructing these processes in an artificial system provides potential applications and offers a new way to understand fundamental biological processes in depth.However,the design of artificial signal transduction systems regulated by artificial enzyme receptors in a predictable and intelligent manner remains a challenge.Herein,benefiting from the polarity-regulated characteristics of Se-containing compounds with artificial glutathione peroxidase(GPx)activity,we constructed an artificial transmembrane signaling receptor with a Se-containing GPx-like recognition head group,a membrane-anchoring group,and a pre-enzyme end group.The artificial supramolecular signal transduction system containing such signal transduction receptors extends the range of signaling systems based on enzyme regulation,which provides a new way to study natural signal processes in cells and artificially regulated biological processes.
