Photoregulating Primer Extension And Transcription Using Azobenzene Linked DNA Template

Oligonucleotide,namely the oligomer of nucleotides,is a kind of biomacromolecules with scientific importance and potential pharmaceutical applications.Its bioconjugation and artificial diversity possess manifold features and broad applications,in comparison to natural one.This thesis focuses on “functionalization and reconstruction of oligonucleotides” and includes two parts.It has been a hot topic in recent years to carry out a series of life activities by artificial reversible manipulation of specific gene expression.In this paper,the photocontrol of primer extension directed by azobenzene modified DNA templates was investigated.DNA templates attached by protective ODNs with 5,6,7 and 8 complementary bases through 4,4?-bis(hydroxymethyl)azobenzene were systematically evaluated by photoregulation of the primer extension without or with UV irradiation.The results showed that much better efficiencies for C3 with 7 protected bases and C2 with 6-base short chains for photoregulating Pri.15 and Pri.17,respectively.Especially for C3,when catalyzed by Vent DNA polymerase,primer extension efficiency was a 1-fold increase upon UV irradiation.Similarly,the extension efficiency(up to 91.4%)with UV irradiation increased 84% for C2 relative to that without UV irradiation,although the background of primer exten sion in the dark was a little higher.This will provide a new strategy or means for studying the gene function,gene expression network to explore the occurrence and development of disease at the molecular level.In the second part of this article,we investigated the behavior of azobenzene units linked nucleic acids in the control of Transcription.The protection of 5,7,9 and 11 bases of the protective chain was confirmed by 4,4?-bis(hydroxymethyl)-azobenzene(azo)Linked DNA template,transcriptional efficiency regulated before and after UV irradiation.The results showed that the T7 NC sequence showed a better light-control transcription effect before 15 min,and the transcription efficiency of T7NC1 and T7NC2 sequences with 7 and 9 protective bases in the first 30 min was significantly lower than that of the normal transcription after UV irradiation.This will provide a new strategy and means for studying the gene function,gene expression network and the occurrence and development of disease at the molecular level.