Enzyme-instructed self-assembly （EISA） offers a facile approach to explore the supramolecular assemblies of small molecules in cellular milieu for a variety of biomedical applications. One of the commonly used enzym...Enzyme-instructed self-assembly （EISA） offers a facile approach to explore the supramolecular assemblies of small molecules in cellular milieu for a variety of biomedical applications. One of the commonly used enzymes is phosphatase, but the study of the substrates of phosphatases mainly focuses on the phos- photyrosine containing peptides. In this work, we examine the EISA of phosphoserine containing small peptides for the first time by designing and synthesizing a series of precursors containing only phosphoserine or both phos- phoserine and phosphotyrosine. Conjugating a phospho- serine to the C-terminal of a well-established self- assembling peptide backbone, （naphthalene-2-1y）-acetyl- diphenylalanine （NapFF）, affords a novel hydrogelation precursor for EISA. The incorporation ofphosphotyrosine, another substrate of phosphatase, into the resulting precursor, provides one more enzymatic trigger on a single molecule, and meanwhile increases the precursors＇ propensity to aggregate after being fully dephosphorylated. Exchanging the positions of phosphorylated serine and tyrosine in the peptide backbone provides insights on how the specific molecular structures influence self-assembling behaviors of small peptides and the subsequent cellular responses. Moreover, the utilization of D-amino acids largely enhances the biostability of the peptides, thus providing a unique soft material for potential biomedical applications.展开更多
The creation of artificial enzymes to mimic natural enzymes remains a great challenge owing to the complexity of the structural arrangement of the essential amino acids in catalytic centers.In this study,we used the p...The creation of artificial enzymes to mimic natural enzymes remains a great challenge owing to the complexity of the structural arrangement of the essential amino acids in catalytic centers.In this study,we used the phosphatase-based enzyme-instructed self-assembly(EISA)to supervise artificial esterases'final structures and catalytic activities.We reported that peptide precursors containing different phosphorylation sites could preorganize into alternated nanostructures and undergo dephosphorylation in the presence of alkaline phosphatase(ALP)with variation in kinetic and thermodynamic profiles.Although identical self-assembly compositions were formed after dephosphorylation,precursors with more enhanced preorganized states tended to better promote ALP dephosphorylation,facilitate further self-assembly,and strengthen the catalytic activities of the final assemblies.We envisioned that our strategy would be useful for further construction and manipulation of various artificial enzymes with superior catalytic activities.展开更多
The radiotherapy modulators used in clinic have disadvantages of high toxicity and low selectivity.For the first time,we used the in situ enzyme-instructed self-assembly(EISA)of a peptide derivative(Nap-GDFDFpYSV)to s...The radiotherapy modulators used in clinic have disadvantages of high toxicity and low selectivity.For the first time,we used the in situ enzyme-instructed self-assembly(EISA)of a peptide derivative(Nap-GDFDFpYSV)to selectively enhance the sensitivity of cancer cells with high alkaline phosphatase(ALP)expression to ionizing radiation(IR).Compared with the in vitro pre-assembled control formed by the same molecule,assemblies formed by in situ EISA in cells greatly sensitized the ALPhigh-expressing cancer cells to y-rays,with a remarkable sensitizer enhancement ratio.Our results indicated that the enhancement was a result of fixing DNA damage,arresting cell cycles and inducing cell apoptosis.Interestingly,in vitro pre-formed assemblies mainly localized in the lysosomes after incubating with cells,while the assemblies formed via in situ EISA scattered in the cell cytosol.The accumulation of these molecules in cells could not be inhibited by endocytosis inhibitors.We believed that this molecule entered cancer cells by diffusion and then in situ self-assembled to form nanofibers under the catalysis of endogenous ALP.This study provides a successful example to utilize intracellular in situ EISA of small molecules to develop selective tumor radiosensitizers.展开更多
文摘Enzyme-instructed self-assembly （EISA） offers a facile approach to explore the supramolecular assemblies of small molecules in cellular milieu for a variety of biomedical applications. One of the commonly used enzymes is phosphatase, but the study of the substrates of phosphatases mainly focuses on the phos- photyrosine containing peptides. In this work, we examine the EISA of phosphoserine containing small peptides for the first time by designing and synthesizing a series of precursors containing only phosphoserine or both phos- phoserine and phosphotyrosine. Conjugating a phospho- serine to the C-terminal of a well-established self- assembling peptide backbone, （naphthalene-2-1y）-acetyl- diphenylalanine （NapFF）, affords a novel hydrogelation precursor for EISA. The incorporation ofphosphotyrosine, another substrate of phosphatase, into the resulting precursor, provides one more enzymatic trigger on a single molecule, and meanwhile increases the precursors＇ propensity to aggregate after being fully dephosphorylated. Exchanging the positions of phosphorylated serine and tyrosine in the peptide backbone provides insights on how the specific molecular structures influence self-assembling behaviors of small peptides and the subsequent cellular responses. Moreover, the utilization of D-amino acids largely enhances the biostability of the peptides, thus providing a unique soft material for potential biomedical applications.
基金supported by the National Science Fund for Distinguished Young Scholars(31825012)the National Natural Science Foundation of China(21875116,31961143004,81921004)+1 种基金the National Key Research and Development Program of China(2017YFC1103502,2018YFC1003401)the China Postdoctoral Science Foundation(2020M680856)。
文摘The creation of artificial enzymes to mimic natural enzymes remains a great challenge owing to the complexity of the structural arrangement of the essential amino acids in catalytic centers.In this study,we used the phosphatase-based enzyme-instructed self-assembly(EISA)to supervise artificial esterases'final structures and catalytic activities.We reported that peptide precursors containing different phosphorylation sites could preorganize into alternated nanostructures and undergo dephosphorylation in the presence of alkaline phosphatase(ALP)with variation in kinetic and thermodynamic profiles.Although identical self-assembly compositions were formed after dephosphorylation,precursors with more enhanced preorganized states tended to better promote ALP dephosphorylation,facilitate further self-assembly,and strengthen the catalytic activities of the final assemblies.We envisioned that our strategy would be useful for further construction and manipulation of various artificial enzymes with superior catalytic activities.
基金supported by the National Natural Science Foundation of China(81971733,31771085 and 81722026)the CAMS Innovation Fund for Medical Sciences(CIFMS,2016-I2M3e022,China)+1 种基金the Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences(2018RC350016 and 2018PT35031,China)the Science Foundation for Distinguished Young Scholars of Tianjin(18JCJQJC47300 and 19JCJQJC62200,China)
文摘The radiotherapy modulators used in clinic have disadvantages of high toxicity and low selectivity.For the first time,we used the in situ enzyme-instructed self-assembly(EISA)of a peptide derivative(Nap-GDFDFpYSV)to selectively enhance the sensitivity of cancer cells with high alkaline phosphatase(ALP)expression to ionizing radiation(IR).Compared with the in vitro pre-assembled control formed by the same molecule,assemblies formed by in situ EISA in cells greatly sensitized the ALPhigh-expressing cancer cells to y-rays,with a remarkable sensitizer enhancement ratio.Our results indicated that the enhancement was a result of fixing DNA damage,arresting cell cycles and inducing cell apoptosis.Interestingly,in vitro pre-formed assemblies mainly localized in the lysosomes after incubating with cells,while the assemblies formed via in situ EISA scattered in the cell cytosol.The accumulation of these molecules in cells could not be inhibited by endocytosis inhibitors.We believed that this molecule entered cancer cells by diffusion and then in situ self-assembled to form nanofibers under the catalysis of endogenous ALP.This study provides a successful example to utilize intracellular in situ EISA of small molecules to develop selective tumor radiosensitizers.
