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Pull‑down
1.1 DNA Pull‑down
1.1.1 Introduction
A biotin‑labeled DNA probe is designed to target a specific genomic or regulatory region of interest. The labeled probe is subsequently captured by streptavidin‑coated magnetic beads via the high‑affinity biotin‑streptavidin interaction. The immobilized DNA probe is then incubated with total protein extracts, allowing proteins that specifically recognize or bind the target DNA sequence to form a bead‑DNA‑protein ternary complex. Following stringent washes to remove non‑specifically bound contaminants, the captured DNA‑protein complexes are eluted under optimized conditions. The eluted proteins are subsequently identified and characterized by Western blot (for validation of known DNA‑binding proteins) or mass spectrometry (for unbiased discovery of novel interacting proteins).
1.1.2 Products
1.1.3 Applications
| Application Area | English Description |
|---|---|
| TF identification and validation | Capture transcription factors from nuclear extracts using biotin‑labeled DNA probes; validate known TF binding via Western blot or unbiasedly identify novel TFs via LC‑MS/MS. Applicable for promoter‑TF interaction validation. |
| Enhancer/silencer interaction profiling | Identify proteins interacting with distal regulatory elements (enhancers, silencers) to elucidate transcriptional regulation mechanisms. Mutant probes can be used to analyze specific binding sites. |
| Protein complex identification | Capture multi‑protein complexes (e.g., DREAM complex) bound to target DNA sequences to resolve the composition of transcriptional regulatory complexes. Applicable for cell cycle and tumor suppression pathways. |
| Comparative binding analysis | Compare DNA‑protein interaction profiles across different treatments, genotypes, or time points to detect regulatory shifts. Useful for studying stress responses and differentiation processes. |
| Drug target screening | Screen proteins interacting with specific nucleic acid sequences as potential drug targets, providing candidate molecules for novel therapeutic strategies in cancer and infectious diseases. |
References:
- Chaparian RR, van Kessel JC. Promoter Pull‑Down Assay: A Biochemical Screen for DNA‑Binding Proteins. Methods Mol Biol. 2021;2346:165‑172. doi: 10.1007/7651_2020_307. PMID: 32803537.
- Müller GA, Engeland K. DNA Affinity Purification: A Pulldown Assay for Identifying and Analyzing Proteins Binding to Nucleic Acids. Methods Mol Biol. 2021;2267:81‑90. doi: 10.1007/978‑1‑0716‑1217‑0_6. PMID: 33786786.
- Jutras BL, Verma A, Stevenson B. Identification of novel DNA‑binding proteins using DNA‑affinity chromatography/pull down. Curr Protoc Microbiol. 2012 Feb; Chapter 1:Unit1F.1. doi: 10.1002/9780471729259.mc01f01s24. PMID: 22307548; PMCID: PMC3564586.
- Dey B, Thukral S, Krishnan S, Chakrobarty M, Gupta S, Manghani C, Rani V. DNA‑protein interactions: methods for detection and analysis. Mol Cell Biochem. 2012 Jun;365(1‑2):279‑99. doi: 10.1007/s11010‑012‑1269‑z. Epub 2012 Mar 8. PMID: 22399265.