Cracking the HBV Code: Unravelling the specificity of Sp1 with G-Quadruplex for next- generation cccDNA inhibitors
Background A guanine-rich DNA structure known as a G4 quadruplex (G4Q), is found in hepatitis B virus (HBV) pre-core promoter and is essential to HBV replication. The host protein Specificity protein 1 (Sp1) is recruited to this G4Q to facilitate HBV transcription. Targeting this Sp1-G4Q interaction may lead to therapeutic interventions against HBV.
Purpose To characterize the interaction of Sp1 and HBV-G4Q
Methods GST-tagged Sp1 (GST-Sp1) was expressed in E. coli and purified using GST affinity column, ion exchange and size exclusion chromatography. DNA binding affinities were assessed by microscale thermophoresis (MST).
Results Recombinant GST-Sp1 protein was produced, purified, and confirmed by SDS-PAGE and peptide mass fingerprinting. Oligonucleotides were folded into G4Q. Estimation of GST-Sp1 and G4Q binding affinity (Kd) is ongoing.
Conclusion GST-Sp1 protein was successfully purified. Ongoing studies will estimate binding affinity and characterize GST-Sp1-G4Q interactions.