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Updated: Apr 7, 2026
Single-Molecule Fluorescence Visualization of DNA Polymerase Dynamics at G-Quadruplexes
Published on: April 4, 2025
[Preparation and identification of DNA G-quadruplex antibody]
Yiqiang Zhang1, Xiaoyu Lan2, Shuang Wang2
1Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan 030001; Department of Biochemistry, Changzhi Medical College, Changzhi 046000, China.
Objective:
To construct a prokaryotic expression plasmid of DNA G-quadruplex antibody, express it in E.coli BL21 (DE3) bacterial expression system, purify and identify the antibody.
Methods:
Chemically synthesized BG4 gene of DNA G-quadruplex antibodies was inserted into pSANG10 plasmid to construct DNA G-quadruplex antibody expression vector pSANG10-BG4. BL21 (DE3) as the host strain was utilized for self-induced expression of the protein. Osmotic lysis method was used for collecting this protein. Thereafter, the protein was purified by histidine tag affinity chromatography and identified by SDS-PAGE and Western blotting. The function of this protein was verified in SW480 colon cancer cells.
Results:
Double enzyme digestion and gene sequencing confirmed that DNA G-quadruplex antibody expression vector was successfully constructed. The relative molecular mass (Mr) of this protein was 30 000 to 37 000. The protein in a soluble form was expressed in the periplasm of BL21. The protein was of the same size as expected.
Conclusion:
The DNA G-quadruplex antibody has been successfully prepared.
