The influence of the G‐quartet structural integrity on the catalytic activity of the G‐quadruplex(G4)was investigated by comparing the G4‐DNAzyme performances of a series of G4s with a G‐vacancy site and a G‐trip...The influence of the G‐quartet structural integrity on the catalytic activity of the G‐quadruplex(G4)was investigated by comparing the G4‐DNAzyme performances of a series of G4s with a G‐vacancy site and a G‐triplex(G‐tri).The results presented herein not only confirm that the structural integrity of the 3'‐end G‐quartet is necessary for G4s to be catalytically competent but also show how to remediate G‐vacancy‐mediated catalytic activity losses via the addition of guanine surrogates in an approach referred to as G‐vacancy complementation strategy that is applicable to parallel G4s only.Furthermore,this study demonstrates that the terminal G‐quartet could act as a proximal coordinating group and cooperate with the flanking nucleotide to activate the hemin cofactor.展开更多
Among the various methods nowadays used to make catenanes and rotaxanes,the metal template synthesis occupies a place of choice,because of its versatility.This contribution shows that,thanks to the richness of their c...Among the various methods nowadays used to make catenanes and rotaxanes,the metal template synthesis occupies a place of choice,because of its versatility.This contribution shows that,thanks to the richness of their chemistry,metal templates can fulfil multiple functions for the construction of these topologically-interesting molecules,from the entwining or threading of their precursors to the simultaneous catalysis of the interlocking reaction.展开更多
Catenanes are molecules made of two or more interlocked rings, and rotaxanes are composed of rings threaded onto axles that look like dumbbells because they are terminated by stoppers large enough to prevent unthreadi...Catenanes are molecules made of two or more interlocked rings, and rotaxanes are composed of rings threaded onto axles that look like dumbbells because they are terminated by stoppers large enough to prevent unthreading （Figure 1） [i].展开更多
Massive efforts are currently being invested to improve the performance,versatility,and scope of applications of nucleic acid catalysts.G-quadruplex(G4)/hemin DNAzymes are of particular interest owing to their structu...Massive efforts are currently being invested to improve the performance,versatility,and scope of applications of nucleic acid catalysts.G-quadruplex(G4)/hemin DNAzymes are of particular interest owing to their structural programmability and chemical robustness.However,optimized catalytic efficiency is still bottleneck and the activation mechanism is unclear.Herein,we have designed a series of parallel G4s with different proximal cytosine(dC)derivatives to fine-tune the hemin-binding pocket for G4-DNAzymes.展开更多
Examples of photoluminescence(PL)are being reported with increasing frequency in a wide range of organisms from diverse ecosystems.However,the chemical basis of this PL remains poorly defined,and our understanding of i...Examples of photoluminescence(PL)are being reported with increasing frequency in a wide range of organisms from diverse ecosystems.However,the chemical basis of this PL remains poorly defined,and our understanding of its potential ecological function is still superficial.Among mammals,recent analyses have identified free-base por-phyrins as the compounds responsible for the reddish ultraviolet-induced photoluminescence(UV-PL)observed in the pelage of springhares and hedgehogs.However,the localization of the pigments within the hair largely remains to be determined.Here,we use photoluminescence multispectral imaging emission and excitation spec-troscopy to detect,map,and characterize porphyrinic compounds in skin appendages in situ.We also document new cases of mammalian UV-PL caused by free-base porphyrins in distantly related species.Spatial distribution of the UV-PL is strongly suggestive of an endogenous origin of the porphyrinic compounds.We argue that reddish UV-PL is predominantly observed in crepuscular and nocturnal mammals because porphyrins are photodegradable.Con-sequently,this phenomenon may not have a specific function in intra-or interspecific communication but rather represents a byproduct of potentially widespread physiological processes.展开更多
文摘The influence of the G‐quartet structural integrity on the catalytic activity of the G‐quadruplex(G4)was investigated by comparing the G4‐DNAzyme performances of a series of G4s with a G‐vacancy site and a G‐triplex(G‐tri).The results presented herein not only confirm that the structural integrity of the 3'‐end G‐quartet is necessary for G4s to be catalytically competent but also show how to remediate G‐vacancy‐mediated catalytic activity losses via the addition of guanine surrogates in an approach referred to as G‐vacancy complementation strategy that is applicable to parallel G4s only.Furthermore,this study demonstrates that the terminal G‐quartet could act as a proximal coordinating group and cooperate with the flanking nucleotide to activate the hemin cofactor.
文摘Among the various methods nowadays used to make catenanes and rotaxanes,the metal template synthesis occupies a place of choice,because of its versatility.This contribution shows that,thanks to the richness of their chemistry,metal templates can fulfil multiple functions for the construction of these topologically-interesting molecules,from the entwining or threading of their precursors to the simultaneous catalysis of the interlocking reaction.
文摘Catenanes are molecules made of two or more interlocked rings, and rotaxanes are composed of rings threaded onto axles that look like dumbbells because they are terminated by stoppers large enough to prevent unthreading （Figure 1） [i].
基金support of the National Natural Science Foundation of China(nos.21977045 and 21635005)the Fundamental Research Funds for the Central Universities(no.02051430210)+5 种基金the Technology Innovation Fund Project of Nanjing University(no.020514913415)the Excellent Research Program of Nanjing University(no.ZYJH004)the funds of Nanjing University(no.020514912216)the Netherlands Organization for Scientific Research(NWO/CW)the CNRS,Agence Nationale de la Recherche(no.ANR-17-CE170010-01)Universitéde Bourgogne and Conseil Régional de Bourgogne(PARI),and the European Union(PO FEDER-FSE Bourgogne 2014/2020 programs).
文摘Massive efforts are currently being invested to improve the performance,versatility,and scope of applications of nucleic acid catalysts.G-quadruplex(G4)/hemin DNAzymes are of particular interest owing to their structural programmability and chemical robustness.However,optimized catalytic efficiency is still bottleneck and the activation mechanism is unclear.Herein,we have designed a series of parallel G4s with different proximal cytosine(dC)derivatives to fine-tune the hemin-binding pocket for G4-DNAzymes.
基金supported by the Elsa-Neumann-Stipendium(Humboldt-Universität zu Berlin)supported by the Fyssen Foundation and the Alexander Von Humboldt Foundation.
文摘Examples of photoluminescence(PL)are being reported with increasing frequency in a wide range of organisms from diverse ecosystems.However,the chemical basis of this PL remains poorly defined,and our understanding of its potential ecological function is still superficial.Among mammals,recent analyses have identified free-base por-phyrins as the compounds responsible for the reddish ultraviolet-induced photoluminescence(UV-PL)observed in the pelage of springhares and hedgehogs.However,the localization of the pigments within the hair largely remains to be determined.Here,we use photoluminescence multispectral imaging emission and excitation spec-troscopy to detect,map,and characterize porphyrinic compounds in skin appendages in situ.We also document new cases of mammalian UV-PL caused by free-base porphyrins in distantly related species.Spatial distribution of the UV-PL is strongly suggestive of an endogenous origin of the porphyrinic compounds.We argue that reddish UV-PL is predominantly observed in crepuscular and nocturnal mammals because porphyrins are photodegradable.Con-sequently,this phenomenon may not have a specific function in intra-or interspecific communication but rather represents a byproduct of potentially widespread physiological processes.
