A strategy based on local spin-state manipulation was achieved through S-modification on single-Fe-atom catalysts(Fe_(1)–NSC).Spectral analyses and theoretical calculations elucidated that a medium-spin reconfigurati...A strategy based on local spin-state manipulation was achieved through S-modification on single-Fe-atom catalysts(Fe_(1)–NSC).Spectral analyses and theoretical calculations elucidated that a medium-spin reconfiguration of Fe species in Fe_(1)–NSC endowed an increased orbital overlap between Fe 3d and O 2p,reinforcing the peroxymonosulfate(PMS)dissociation kinetics.Consequently,Fe_(1)–NSC delivered excellent performance in PMS conversion and pollutant degradation.The specific activity of PMS activation over Fe_(1)–NSC reached 36.1×10^(–3)L min^(-1)m^(-2),4.2-folds that of Fe_(1)–NC(8.61×10^(–3)L min^(-1)m^(-2))and superior to the state-of-the-art catalysts reported to date.Importantly,the atomic spin-state modulation via Smodification can extend to other metals(Mn,Co and Cu)for improved PMS activation with>3 times higher than those without S-modification.This work provides a universal scheme for electronic configuration regulation and highlights the significance of local environment modulation in designing highperformance catalysts for PMS activation.展开更多
Here we tell a 20-year long story.It began with an easily overlooked DNA degradation(Dnd)phenomenon during electrophoresis and eventually led to the discovery of an unprecedented DNA sulfur modification governed by fi...Here we tell a 20-year long story.It began with an easily overlooked DNA degradation(Dnd)phenomenon during electrophoresis and eventually led to the discovery of an unprecedented DNA sulfur modification governed by five dnd genes.This unusual DNA modification,called phosphorothioation,is the first physiological modification identified on the DNA backbone,in which the nonbridging oxygen is replaced by sulfur in a sequence selective and stereo-specific manner.Homologous dnd gene clusters have been identified in diverse and distantly related bacteria and thus have drawn immediate attention of the entire microbial scientific community.Here,we summarize the progress in chemical,genetic,enzymatic,bioinformatical and analytical aspects of this novel postreplicative DNA modification.We also discuss perspectives on the physiological functions of the DNA phosphorothioate modification in bacteria and their implications.展开更多
Modified deoxy-and ribo-nucleoside triphosphates are chemically synthesized in multiple steps due to the protection and deprotection of the nucleoside functionalities.To conveniently synthesize the S-modified triphosp...Modified deoxy-and ribo-nucleoside triphosphates are chemically synthesized in multiple steps due to the protection and deprotection of the nucleoside functionalities.To conveniently synthesize the S-modified triphosphates for enzymatically preparing phosphorothioate DNAs and RNAs(PS-DNA and PS-RNA) as potential therapeutics,herein we report a one-pot strategy to synthesize the deoxy-and ribo-nucleoside 5'-(α-P-thio)triphosphates(dNTPαS and NTPαS) without protecting any nucleoside functionalities.This facile synthesis is achieved by treating the nucleosides with a mild phosphitylating reagent,reacting selectively with the 5'-hydroxyl group of each unprotected nucleoside,followed by sulfurization and hydrolysis to afford the crude dNTPαS and NTPαS analogs(mixtures of Sp and Rp diastereomers).We also demonstrated that after just simple precipitation(without HPLC and ion-exchange purification),the quality of the synthesized dNTPαS and NTPαS analogs is excellent for direct DNA polymerization and RNA transcription,respectively.Since Klenow DNA polymerase and T7 RNA polymerase accept the Sp diastereomers of dNTPαS and NTPαS analogs,respectively,while the Rp diastereomers are neither substrates nor inhibitors,the diastereomerically-pure PS-DNAs and PS-RNAs can be conveniently synthesized enzymatically.展开更多
基金the financial support of the National Natural Science Foundation of China(Nos.52260006,52000097,52170082 and 51938007)he Natural Science Foundation of Jiangxi Province(Nos.20242BAB23049,20243BCE51075 and 20212ACB203008)。
文摘A strategy based on local spin-state manipulation was achieved through S-modification on single-Fe-atom catalysts(Fe_(1)–NSC).Spectral analyses and theoretical calculations elucidated that a medium-spin reconfiguration of Fe species in Fe_(1)–NSC endowed an increased orbital overlap between Fe 3d and O 2p,reinforcing the peroxymonosulfate(PMS)dissociation kinetics.Consequently,Fe_(1)–NSC delivered excellent performance in PMS conversion and pollutant degradation.The specific activity of PMS activation over Fe_(1)–NSC reached 36.1×10^(–3)L min^(-1)m^(-2),4.2-folds that of Fe_(1)–NC(8.61×10^(–3)L min^(-1)m^(-2))and superior to the state-of-the-art catalysts reported to date.Importantly,the atomic spin-state modulation via Smodification can extend to other metals(Mn,Co and Cu)for improved PMS activation with>3 times higher than those without S-modification.This work provides a universal scheme for electronic configuration regulation and highlights the significance of local environment modulation in designing highperformance catalysts for PMS activation.
文摘Here we tell a 20-year long story.It began with an easily overlooked DNA degradation(Dnd)phenomenon during electrophoresis and eventually led to the discovery of an unprecedented DNA sulfur modification governed by five dnd genes.This unusual DNA modification,called phosphorothioation,is the first physiological modification identified on the DNA backbone,in which the nonbridging oxygen is replaced by sulfur in a sequence selective and stereo-specific manner.Homologous dnd gene clusters have been identified in diverse and distantly related bacteria and thus have drawn immediate attention of the entire microbial scientific community.Here,we summarize the progress in chemical,genetic,enzymatic,bioinformatical and analytical aspects of this novel postreplicative DNA modification.We also discuss perspectives on the physiological functions of the DNA phosphorothioate modification in bacteria and their implications.
基金supported by USA NIH(GM095086)the Georgia Cancer Coalition(GCC) Distinguished Cancer Clinicians and ScientistsUSA National Science Foundation(MCB-0824837)
文摘Modified deoxy-and ribo-nucleoside triphosphates are chemically synthesized in multiple steps due to the protection and deprotection of the nucleoside functionalities.To conveniently synthesize the S-modified triphosphates for enzymatically preparing phosphorothioate DNAs and RNAs(PS-DNA and PS-RNA) as potential therapeutics,herein we report a one-pot strategy to synthesize the deoxy-and ribo-nucleoside 5'-(α-P-thio)triphosphates(dNTPαS and NTPαS) without protecting any nucleoside functionalities.This facile synthesis is achieved by treating the nucleosides with a mild phosphitylating reagent,reacting selectively with the 5'-hydroxyl group of each unprotected nucleoside,followed by sulfurization and hydrolysis to afford the crude dNTPαS and NTPαS analogs(mixtures of Sp and Rp diastereomers).We also demonstrated that after just simple precipitation(without HPLC and ion-exchange purification),the quality of the synthesized dNTPαS and NTPαS analogs is excellent for direct DNA polymerization and RNA transcription,respectively.Since Klenow DNA polymerase and T7 RNA polymerase accept the Sp diastereomers of dNTPαS and NTPαS analogs,respectively,while the Rp diastereomers are neither substrates nor inhibitors,the diastereomerically-pure PS-DNAs and PS-RNAs can be conveniently synthesized enzymatically.
