Description:
Recombinant monoclonal antibody to DNA/RNA G-quadruplex. Manufactured using AbAb’s Recombinant Platform with variable regions (i.e. specificity) from the phage display derived scfv BG4.
UniProt Accession Number of Target Protein: n/a
Alternative Name(s) of Target: G4 quadruplex
Immunogen: DNA/RNA G-quadruplex.
Specificity: Binds with high selectivity and low nanomolar affinity to DNA and RNA G-quadruplex structures.
Application Notes: This antibody has been shown (by ELISA) to bind selectively to G-quadruplex forming DNA and RNA structures. Please that Fab-based versions as well as scFvs, with and without Flag-tag are available, which needs to be considered when replicating published methods. Tsai et al. (2022 et al. PMID: 36440760), report similar activtiy between whole-antibody and scFv-based versions of BG4. Weldon et al. (2016, PMID: 27820800) used Ab00174-1.1 to identify G-quadruplexes in long functional RNAs using an electrophoretic mobility shift assay (EMSA). The mouse IgG1 version of BG4 was shown to have weak cross-reactivity with iMotif structures (2018, PMID: 29686376). iMotif structures can be detected selectively using our anti-iMotif antibody Ab01462.
Antibody first published in: Biffi G, Tannahill D, McCafferty J, Balasubramanian S. Quantitative visualization of DNA G-quadruplex structures in human cells. Nat Chem. 2013 Mar;5(3):182-6. PMID:23422559
Note on publication: Describes generation of a G-quadruplex-specific antibody using phage display and the in vitro selection (using ELISA and CD) of a structure-specific antibody probe that binds with high selectivity and low nanomolar affinity to DNA G-quadruplex structures called BG4.
Comparison of the binding of full length IgG and Fab versions of the BG4 antibody Binding curves for the association of BG4 as a full-length murine IgG1 (left panel) and a human Fab fragment (right panel) with a DNA G-quadruplex oligo (from human MYC gene promoter: 5’ [Btn] TGA GGG T GGG TA GGG T GGG TAA), a RNA G-quadruplex oligo (frum human NRAS 5’UTR RNA :5’ [Btn] TGA GGG T GGG TA GGG T GGG TAA) and a non- G-quadruplex forming negative control oliogo (mutated MYC sequence: 5′ [Btn] TGA GAG T GAG TA GAG T GAG TAA) as determined by ELISA. To form the G-quadruplex, the oligos (at 5 uM) were annealed in 10 mM Tris, 100 mM KCl (pH 7.4) and heated to 95 °C for 10 minutes before slowly cooling to RT. The ELISA was performed by binding the biotinylated oligos (50 nM) to a steptavidin plate for 1 hour. After washing, the plate was blocked and incubated with serial dilutions of antibody for 1 hour at RT. The plates were washed and then incubated with an anti-mouse or anti-human, HRP-coupled secondary antibody. After washing, TMB substrate was added, the reaction stopped with HCl and the absorbance measured at 450 nm on a plate reader. Each experimental data point was determined in triplicate. This method is described in the Nature Chemistry paper (doi: 10.1038/NCHEM.1548, dos: 10.1038/NCHEM.1805). Data courtesy of Darcie Mulhearn and Dr. David Tannahill, Balasubramanian Group, Department of Chemistry, University of Cambridge.