DNA is generally assumed as a right-handed double helix and Z-DNA is a special kind of left-handed DNA infrequently found in nature. However, the finding of a zero linking number topoisomer supports a hypothesis that ...DNA is generally assumed as a right-handed double helix and Z-DNA is a special kind of left-handed DNA infrequently found in nature. However, the finding of a zero linking number topoisomer supports a hypothesis that the two strands of DNA are winding ambidextrously, rather than plectonemically. It logically leads to a notion that the left-handed DNA is as common as right-handed DNA and the amount of left-handed DNA in a positively supercoiled plasmid prevails that of the right-handed DNA. In this report, the helical repeat of left-handed DNA, 12 bp per turn, was determined by a new method. How the positively supercoiled DNA was generated in hyperthermophiles and why their DNA can withstand the extreme high temperature are answered from an alternative theory.展开更多
Since the discovery of left-handed G-quadruplex(L-G4)structure formed by natural DNA,there has been a growing interest in its potential functions.This study utilised it to catalyse enantioselective Diels-Alder reactio...Since the discovery of left-handed G-quadruplex(L-G4)structure formed by natural DNA,there has been a growing interest in its potential functions.This study utilised it to catalyse enantioselective Diels-Alder reactions,considering its different optical rotation compared to an ordinary G4.It was determined that when L-G4 was used with a combination of copper(Ⅱ)ions,there was a good enantioselectivity(-52%ee)without further addition of ligands.When further consideration was given by adding G4 ligands,G4 was further stabilised,even obtaining a better enantioselectivity(up to-80%ee).Moreover,when using ligands that have regulatory effects on G4,the ee value can be adjusted.In this work,a minimal left-handed G4 was reported.A follow-up study was also con ducted,which recovers that the minimal left-handed G4 remains its catalytic effect and enantioselectivity,but is not so effective as the former case.This indicates that a complete G4 structure is relatively conducive to chiral catalysis.展开更多
N umerous neurological disorders negatively impact the nervous system,either through loss of neurons or by disrupting the normal functioning of neural networks.These impairments manifest as cognitive defects,memory lo...N umerous neurological disorders negatively impact the nervous system,either through loss of neurons or by disrupting the normal functioning of neural networks.These impairments manifest as cognitive defects,memory loss,behavioral abnormalities,and motor dysfunctions.Decades of research have significantly advanced our understanding of the pathophysiology underlying neurodegene rative diseases,including Alzheimer's disease(AD),Parkinson's disease,amyotrophic lateral sclerosis,and others.展开更多
文摘DNA is generally assumed as a right-handed double helix and Z-DNA is a special kind of left-handed DNA infrequently found in nature. However, the finding of a zero linking number topoisomer supports a hypothesis that the two strands of DNA are winding ambidextrously, rather than plectonemically. It logically leads to a notion that the left-handed DNA is as common as right-handed DNA and the amount of left-handed DNA in a positively supercoiled plasmid prevails that of the right-handed DNA. In this report, the helical repeat of left-handed DNA, 12 bp per turn, was determined by a new method. How the positively supercoiled DNA was generated in hyperthermophiles and why their DNA can withstand the extreme high temperature are answered from an alternative theory.
基金This work was supported by the National Natural Science Foundation of China(Nos.21432008,91753201,and 21721005).
文摘Since the discovery of left-handed G-quadruplex(L-G4)structure formed by natural DNA,there has been a growing interest in its potential functions.This study utilised it to catalyse enantioselective Diels-Alder reactions,considering its different optical rotation compared to an ordinary G4.It was determined that when L-G4 was used with a combination of copper(Ⅱ)ions,there was a good enantioselectivity(-52%ee)without further addition of ligands.When further consideration was given by adding G4 ligands,G4 was further stabilised,even obtaining a better enantioselectivity(up to-80%ee).Moreover,when using ligands that have regulatory effects on G4,the ee value can be adjusted.In this work,a minimal left-handed G4 was reported.A follow-up study was also con ducted,which recovers that the minimal left-handed G4 remains its catalytic effect and enantioselectivity,but is not so effective as the former case.This indicates that a complete G4 structure is relatively conducive to chiral catalysis.
基金supported by the National Institute on Aging(Nos.AG000723 and AG000578)(to VAB)the Fondation Sante(No.19656),Greece 2.0+1 种基金the National Recovery and Resilience Plan’s flagship program TAEDR-0535850the European Research Council(No.101077374-Synapto Mitophagy)(to KP)。
文摘N umerous neurological disorders negatively impact the nervous system,either through loss of neurons or by disrupting the normal functioning of neural networks.These impairments manifest as cognitive defects,memory loss,behavioral abnormalities,and motor dysfunctions.Decades of research have significantly advanced our understanding of the pathophysiology underlying neurodegene rative diseases,including Alzheimer's disease(AD),Parkinson's disease,amyotrophic lateral sclerosis,and others.
