CN106905399B - A kind of light control method that double-stranded DNA B-Z conformation is mutually converted - Google Patents

Abstract

The present invention provides a kind of light control method that double-stranded DNA B-Z conformation is mutually converted, and belongs to molecular biology and field of nucleic acid chemistry.This method passes through DNA standard solid-phase synthetic method first, then synthesis passes through the illumination of 365nm, 254nm wavelength with the modification short chain DNA of guanine, and reversible control B-form DNA and Z-form DNA mutually convert.This method control DNA Conformation transition reversible using illumination, has space-time controllability in.

Description

A kind of light control method that double-stranded DNA B-Z conformation is mutually converted

Technical field

The invention belongs to molecular biology and field of nucleic acid chemistry, it is related to mutually converting for a kind of B-form DNA and Z-form DNA The method of light-operated reversible control.

Background technique

There are three types of major confonnationals by DNA: A-DNA, b form dna and Z-DNA.B form dna is the right hand that Watson and Click is proposed Spin model is the conformation of most of duplex DNA in physiological conditions.A-DNA is also right-handed helix, but breechblock it is wider and Short, major groove area is relatively narrow and deep, and ditch area is more shallow and wide.Aform DNA can be obtained by b form dna is partially dehydrated, usually in non-physiological condition Lower formation, and in vivo, there may be in the compound of the hybridization of DNA-RNA or DNA and enzyme by A-DNA.Z-DNA with upper two kinds not Together, be left hand helix, phosphate distribution is in Z-shaped, an only major groove and without ditch.The alternately arranged sequence of purine-pyrimidine Especially d (GC) alternate sequence Z-DNA easy to form is more likely formed Z-DNA if wherein C methylates.Z-form DNA can be by Specific albumen is identified, and this process is of great significance to the regulation of transcription.B form dna and Z-DNA in vivo by Directly observe.

Between the various secondary structures of DNA can phase co-conversion, for large biological molecule, it is this transformation have it is important Physiological function.But scientists do not form the understanding of system to the structure of Z-DNA and its function always, study Z- at present The means of DNA are all the function of removing to probe into certain Z-DNA by Z-DNA binding protein, therefore, the light-operated reversible that the present invention develops Control B-form DNA and Z-form DNA the method mutually converted, the operation and regulation to large biological molecule may be implemented, for phase The research for closing the molecular mechanism of physiological action is particularly important.

Summary of the invention

It is a kind of with space-time controllability technical problem to be solved by the present invention lies in providing and small to living body injury, The method mutually converted based on the guanine of modification using light control double-stranded DNA B-Z conformation.

The technical scheme is that

1), using DNA solid-phase synthesis, the short chain DNA containing a such as modification guanine for logical formula (I) is synthesized, then Double-stranded DNA is formed with after complementary strand annealing；Wherein, R1 is one of phenyl, 2- naphthalene or 2- fluorenyl；

2) in the NaCl solution of 0.2-4 mol/L, with wavelength 365nm illumination 10 minutes, then 37 degree warm bath 6 hours, DNA conformation turns to Z by B；With the DNA10 minute of wavelength 254nm illumination Z conformation, then 37 degree warm bath 6 hours, may be implemented DNA Conformation is turned to the reversible control of B by Z.

The principle of the present invention figure is as shown in Figure 1.

The advantages and beneficial effects of the present invention are:

1, what is used in the present invention to the control of the B-Z reversible transition of DNA conformation is illumination, with space-time controllability, and And it is small to living body injury, it is conducive to in-situ control.

2, the B-Z conversion of the DNA conformation in the present invention is reversible, so that this method is very suitable for studying B-Z conversion phase Close the molecular mechanism of physiological function.

Detailed description of the invention

Fig. 1 DNA configuration B-Z converts the working principle diagram of light-operated reversible control

CD spectrum under Fig. 2 double-stranded DNA difference NaCl concentration

The conversion of Fig. 3 B-Z configuration light-operated reversible

Specific embodiment

By following detailed description combination attached drawing it will be further appreciated that the features and advantages of the invention.Provided implementation Example is only the explanation to the method for the present invention, remaining content without limiting the invention in any way announcement.

Embodiment 1

1, DNA synthesis of the present invention containing modification guanine

Using DNA solid-phase synthesis synthesis containing modification guanine DNA (Angew.Chem.Int.Ed.2008,47, 8839-8842), sequence CGCXCGCGCGC, X indicate that the guanine of structural modification in Fig. 1, complementary DNA are general sequence GCGCGCGCGCG.It anneals in 7.0,5 mM/ls of pH of buffer solution of sodium phosphate, forms double-stranded DNA.

2, the influence that the concentration of NaCl changes b form dna to Z-DNA structure

At 10 DEG C, under conditions of DNA double chain concentration is 10 μM, NaCl is added into solution, until final concentration is respectively 1,2, 3,4,5 mol/Ls, and the CD spectrogram of solution is measured respectively, as a result as shown in Figure 2, it can be seen that the absorption value at 295nm is by just Change to negative value, show to increase with NaCl concentration, DNA conformation is converted from B to Z.

3, the light control DNA B-Z configuration reversible transition of different wave length

In double stranded DNA solutions, as shown in figure 3, NaCl is added to final concentration of 3.5 mol/L, CD spectrogram is measured, is Fig. 3 green line；Then 365nm illumination 10 minutes, then 37 degree warm bath 6 hours, measure CD value, are shown in Fig. 3 red line.Then wavelength 254nm illumination 10 minutes, then 37 degree warm bath 6 hours, measured CD value, were shown in the light blue line of Fig. 3.365nm illumination 10 minutes again, Then 37 degree warm bath 6 hours measure CD value, are shown in the dark blue line of Fig. 3.Then wavelength 254nm illumination 10 minutes, then 37 degree temperature Bath 6 hours measures CD value, is shown in the pink line of Fig. 3.The change that absorption value at the 295nm of CD spectrogram occurs with illumination, shows The reversible regulation that Compound eye converts DNA conformation B-Z.

Claims (1)

1. a kind of method mutually converted based on the guanine of modification using light control double-stranded DNA B-Z conformation, feature are existed In including the following steps:

1) DNA solid-phase synthesis is utilized, the short chain DNA of modification guanine of the synthesis containing one such as (I) is then moved back with complementary strand Double-stranded DNA is formed after fire；

2) in the NaCl solution of 3.5 mol/Ls, with wavelength 365nm illumination 10 minutes, then 37 degree warm bath 6 hours, DNA structure As turning to Z by B；With the DNA10 minute of wavelength 254nm illumination Z conformation, then 37 degree warm bath 6 hours, may be implemented DNA conformation The reversible control of B is turned to by Z；