Di-Methyl-TP53 (K370) Antibody

What is Di-Methyl-TP53 (K370) Antibody and what specifically does it detect?

Di-Methyl-TP53 (K370) Antibody is a rabbit polyclonal antibody specifically designed to detect endogenous levels of p53 protein only when di-methylated at lysine 370 (K370) . This specificity is crucial for investigating the unique functional state of p53 that arises from this particular post-translational modification. The antibody does not cross-react with non-methylated p53 or other methylation states at this site, making it a precise tool for studying this specific modification .

What are the validated applications for Di-Methyl-TP53 (K370) Antibody?

The Di-Methyl-TP53 (K370) Antibody has been validated for multiple research applications:

• Western Blotting (WB): Typically used at dilutions of 1:500-1:2000

• Enzyme-Linked Immunosorbent Assay (ELISA): Effective at dilutions up to 1:20000

• Immunohistochemistry on paraffin-embedded tissues (IHC-P): Recommended at dilutions of 1:100-1:300

• Immunofluorescence (IF): Optimal at dilutions of 1:50-1:200

Western blot analysis using this antibody has been validated in cell lines such as MCF7, demonstrating its utility in detecting endogenous di-methylated p53 .

What are the storage and handling requirements for optimal antibody performance?

For optimal stability and performance, Di-Methyl-TP53 (K370) Antibody should be stored at -20°C for up to one year from the date of receipt . The antibody is typically formulated as a liquid in PBS containing 50% glycerol, 0.5% BSA, and 0.02% sodium azide . It's recommended to avoid repeated freeze-thaw cycles as these can compromise antibody integrity and performance . The standard concentration of commercially available antibody is 1 mg/ml .

How should Di-Methyl-TP53 (K370) Antibody be validated before use in experimental systems?

Proper validation of the Di-Methyl-TP53 (K370) Antibody should include:

• Positive and negative controls: Use cell lines known to express di-methylated p53 at K370 (like MCF7) as positive controls . For negative controls, consider using p53-null cell lines or cells treated with methyltransferase inhibitors.

• Peptide competition assay: Incubating the antibody with an excess amount of the competitor methyl-p53 peptide before application to verify specificity .

• Knockdown/knockout verification: Comparison of antibody signal in wild-type cells versus those with SETDB1 knockdown (potential K370 methyltransferase) or using p53 knockout cells reconstituted with K370 mutants that cannot be methylated .

• Cross-reactivity testing: Verify that the antibody does not detect mono-methylated K370 or other methylated lysine residues in p53 by comparing with specific antibodies for these modifications .

What are the key methodological considerations when using Di-Methyl-TP53 (K370) Antibody for Western blotting?

When utilizing Di-Methyl-TP53 (K370) Antibody for Western blotting, researchers should consider:

• Sample preparation: Ensure proper cell lysis using buffers that preserve post-translational modifications (include phosphatase and deacetylase inhibitors since these modifications can influence methylation patterns) .

• Dilution optimization: Start with the manufacturer's recommended 1:500-1:2000 dilution range, but optimize for your specific experimental system .

• Secondary antibody selection: Use appropriate anti-rabbit IgG secondary antibodies. Compatible options include goat anti-rabbit IgG conjugated with HRP, AP, biotin, or fluorescent tags .

• Controls: Include both positive controls (cells known to express di-methylated p53) and negative controls (p53-null cells or K370R mutant-expressing cells) .

• Protein loading: Due to the often low abundance of specifically modified p53, consider immunoprecipitation with a general p53 antibody before Western blotting with the Di-Methyl-K370 specific antibody .

How can Di-Methyl-TP53 (K370) Antibody be used effectively in immunoprecipitation studies?

For effective immunoprecipitation (IP) protocols using Di-Methyl-TP53 (K370) Antibody:

• Cell preparation: Treat cells with appropriate stimuli that induce p53 activation, such as DNA-damaging agents like doxorubicin, to increase the levels of di-methylated p53 .

• IP protocol:

  • Lyse cells in appropriate buffer (e.g., containing 100 mM Na₂H₂PO₄, 150 mM NaCl, 2 mM EDTA, 5 mM DTT, 1% Triton X-100, and protease inhibitors)

  • Pre-clear lysates with protein A-beads

  • Incubate with Di-Methyl-TP53 (K370) Antibody (typically 2-5 μg per 500 μg of total protein)

  • Add protein A-beads and incubate overnight at 4°C

  • Wash extensively with buffer containing 0.1-1% detergent

  • Elute using either SDS sample buffer, excess competing peptide, or low pH buffer

• Sequential IP: Consider performing sequential IP with a general p53 antibody followed by Di-Methyl-K370 antibody to enrich for the specifically modified form .

What is the functional significance of p53 di-methylation at K370 compared to other p53 modifications?

p53 di-methylation at K370 represents a critical regulatory mechanism with distinct functional outcomes:

• Activation vs. Inhibition: Di-methylation at K370 activates p53's transcriptional activity, in direct contrast to mono-methylation at the same residue, which inhibits p53 activity . This creates a methylation "switch" that can fine-tune p53 function.

• Protein-protein interactions: Di-methylation at K370 promotes the recruitment of the co-activator 53BP1 (p53 binding protein 1), enhancing p53's ability to activate target genes . This interaction is critical for p53's tumor suppressor function.

• Cross-talk with other modifications: K370 di-methylation exists within a complex network of post-translational modifications. For instance, Set7/9-dependent methylation at K372 inhibits K370 methylation by Smyd2 . Additionally, methylation at K370 affects subsequent acetylation events that further regulate p53 stability and activity .

• DNA binding regulation: While mono-methylation of K370 prevents p53 binding to DNA, di-methylation appears to enhance this interaction, demonstrating how subtle changes in methylation status can dramatically alter p53 function .

How does p53 di-methylation at K370 relate to p53 stability and turnover in cancer cells?

p53 di-methylation at K370 plays a significant role in regulating protein stability and turnover:

• Half-life extension: Research suggests that di-methylation at K370, potentially mediated by SETDB1 in some contexts, can significantly extend the half-life of p53, particularly mutant forms such as p53R249S found in liver cancer cells .

• Degradation regulation: Knockdown of methyltransferases like SETDB1 that may be responsible for K370 di-methylation promotes more rapid degradation of p53, suggesting this modification protects p53 from proteasomal degradation .

• MDM2 interaction: Di-methylation may interfere with the interaction between p53 and MDM2, the E3 ubiquitin ligase primarily responsible for p53 degradation, though the precise mechanism requires further investigation .

• Mutant p53 stabilization: Particularly interesting is the observation that di-methylation at K370 may contribute to the characteristic stability of mutant p53 proteins in cancer cells, potentially contributing to their gain-of-function activities .

What enzymes are involved in regulating p53 K370 methylation states?

The methylation status of p53 at K370 is regulated by a dynamic interplay of methyltransferases and demethylases:

• Mono-methylation by Smyd2: The SET/MYND Domain-2 (SMYD2) methyltransferase catalyzes mono-methylation of K370, which inhibits p53's DNA binding and transcriptional activity .

• Di-methylation: While the specific methyltransferase responsible for di-methylation at K370 has not been definitively identified in all contexts, some research suggests SETDB1 may play this role in certain cancer cells .

• Demethylation by LSD1: Lysine Specific Demethylase 1 (LSD1) removes methyl groups from K370, primarily converting di-methylated K370 to the mono-methylated form . This demethylation decreases p53 activity by reducing the binding of the co-activator 53BP1 to p53.

• Regulatory cross-talk: Set7/9, which methylates p53 at K372, inhibits Smyd2-mediated K370 mono-methylation, creating a regulatory hierarchy among these modifications .

How can Di-Methyl-TP53 (K370) Antibody be used to study methylation-acetylation interplay in p53 regulation?

Investigating the methylation-acetylation interplay using Di-Methyl-TP53 (K370) Antibody requires sophisticated experimental approaches:

• Sequential chromatin immunoprecipitation (ChIP):

  • First ChIP with Di-Methyl-TP53 (K370) Antibody

  • Re-ChIP with antibodies against acetylated p53 (e.g., acetyl-K373/K382)

  • Analyze bound DNA to determine if these modifications co-occur at specific promoters

• Co-immunoprecipitation studies:

  • Immunoprecipitate with Di-Methyl-TP53 (K370) Antibody

  • Probe for acetylated forms using acetylation-specific antibodies

  • This reveals whether these modifications coexist on the same p53 molecules

• In vitro modification assays:

  • Use synthetic p53 peptides that are pre-methylated at K370

  • Test whether this methylation affects subsequent acetylation by p300/CBP

  • Analyze using mass spectrometry or modification-specific antibodies

• Inhibitor studies:

  • Treat cells with methyltransferase or acetyltransferase inhibitors

  • Analyze changes in modification patterns using Di-Methyl-TP53 (K370) Antibody

  • This reveals the hierarchy and interdependence of these modifications

What are the best approaches for analyzing p53 K370 di-methylation in response to DNA damage?

To effectively analyze p53 K370 di-methylation in response to DNA damage:

• Time-course experiments:

  • Treat cells with DNA-damaging agents (e.g., doxorubicin, etoposide, or UV radiation)

  • Harvest cells at multiple time points (0, 1, 3, 6, 12, 24 hours)

  • Analyze di-methylation at K370 using the specific antibody

  • Compare with other p53 modifications to establish temporal relationships

• Chromatin immunoprecipitation (ChIP):

  • Perform ChIP with Di-Methyl-TP53 (K370) Antibody before and after DNA damage

  • Analyze occupancy at p53 target gene promoters (e.g., p21, PUMA, BAX)

  • This reveals how this modification affects p53's genomic binding patterns

• Cell fractionation:

  • Separate nuclear and cytoplasmic fractions

  • Analyze di-methylation patterns in each compartment

  • Determine if DNA damage affects the subcellular localization of di-methylated p53

• Mass spectrometry validation:

  • Immunoprecipitate p53 after DNA damage

  • Perform liquid chromatography with tandem mass spectrometry (LC-MS/MS)

  • Quantify the relative abundance of various methylation states at K370

How can Di-Methyl-TP53 (K370) Antibody be used to investigate the relationship between p53 K370 di-methylation and cancer progression?

To investigate the relationship between p53 K370 di-methylation and cancer progression:

• Tissue microarray analysis:

  • Perform immunohistochemistry using Di-Methyl-TP53 (K370) Antibody on cancer tissue microarrays

  • Compare expression patterns across cancer stages and grades

  • Correlate with clinical outcomes and other molecular markers

• Cell line panel screening:

  • Screen diverse cancer cell lines using Western blot with Di-Methyl-TP53 (K370) Antibody

  • Correlate methylation patterns with p53 mutation status, cancer type, and aggressiveness

  • This may reveal cancer-specific patterns of this modification

• Functional studies in cancer models:

  • Generate cell lines expressing p53 K370 mutants that cannot be methylated (K370R) or mimic methylation

  • Compare their tumorigenic properties (proliferation, invasion, drug resistance)

  • Use xenograft models to assess in vivo relevance of this modification

• Enzyme modulation studies:

  • Manipulate levels of methyltransferases (SETDB1, Smyd2) and demethylases (LSD1)

  • Monitor changes in di-methylation at K370 and correlate with cancer phenotypes

  • This approach can establish causal relationships between the enzymes, modification, and cancer properties

What are common troubleshooting issues when using Di-Methyl-TP53 (K370) Antibody and how can they be addressed?

When working with Di-Methyl-TP53 (K370) Antibody, researchers may encounter several common issues:

• Weak or no signal in Western blot:

  • Increase antibody concentration or protein loading

  • Consider immunoprecipitation to enrich for p53 before blotting

  • Verify p53 expression and induction (with DNA damage agents)

  • Ensure that modifications are preserved with appropriate inhibitors in lysis buffers

• Non-specific bands:

  • Optimize antibody dilution (try 1:1000 as starting point)

  • Increase blocking time or change blocking agent

  • Include competing peptide controls

  • Use p53-null cells as negative controls

• Inconsistent results across experiments:

  • Standardize cell treatment protocols

  • Maintain consistent timing for fixation/extraction

  • Ensure antibody storage conditions are optimal

  • Prepare fresh working solutions for each experiment

• Poor signal in IHC/IF:

  • Optimize antigen retrieval methods (try citrate buffer pH 6.0)

  • Extend primary antibody incubation time (overnight at 4°C)

  • Use signal amplification systems

  • Ensure tissues are properly fixed and processed

How can researchers distinguish between mono- and di-methylation at K370 in their experimental systems?

Distinguishing between different methylation states at K370 requires careful experimental approaches:

• Use of specific antibodies:

  • Compare results using specific antibodies for mono-methylated K370 and di-methylated K370

  • Perform parallel experiments with both antibodies on identical samples

• Mass spectrometry analysis:

  • Perform LC-MS/MS analysis on immunoprecipitated p53

  • This can quantitatively distinguish between un-, mono-, and di-methylated forms of K370

• Enzyme manipulation:

  • Overexpress or deplete specific enzymes (e.g., Smyd2 for mono-methylation, LSD1 for demethylation)

  • Monitor changes in the signal detected by Di-Methyl-K370 antibody versus Mono-Methyl-K370 antibody

• Peptide competition assays:

  • Perform Western blots with antibody pre-incubated with mono-methylated or di-methylated K370 peptides

  • This reveals the specificity of the antibody for different methylation states

What emerging research areas might benefit from using Di-Methyl-TP53 (K370) Antibody?

Di-Methyl-TP53 (K370) Antibody could be valuable in several cutting-edge research areas:

• Single-cell analysis of p53 modifications:

  • Adapting Di-Methyl-TP53 (K370) Antibody for single-cell immunofluorescence or CyTOF

  • This would reveal cell-to-cell heterogeneity in p53 methylation states within tumors or tissues

• Liquid biopsy development:

  • Exploring whether di-methylated p53 can be detected in circulating tumor cells or extracellular vesicles

  • Potential development as a cancer biomarker

• Drug development targeting p53 methylation:

  • Screening compounds that modulate K370 methylation status

  • Using the antibody as a readout in high-throughput drug screens

• Combinatorial epigenetic therapy assessment:

  • Monitoring changes in p53 methylation during treatment with epigenetic drugs

  • Understanding how these therapies affect p53 function through methylation

How might novel technologies enhance the utility of Di-Methyl-TP53 (K370) Antibody in p53 research?

Emerging technologies could significantly expand applications of Di-Methyl-TP53 (K370) Antibody:

• Spatial transcriptomics integration:

  • Combining immunohistochemistry using Di-Methyl-TP53 (K370) Antibody with spatial transcriptomics

  • This would correlate p53 methylation status with gene expression patterns in tissue microenvironments

• CRISPR-based modification screens:

  • Using the antibody as a readout in CRISPR screens targeting chromatin modifiers

  • Identifying novel regulators of p53 K370 di-methylation

• Proximity labeling approaches:

  • Adapting techniques like BioID or APEX2 with Di-Methyl-TP53 (K370) Antibody

  • Identifying proteins that specifically interact with di-methylated p53

• Intrabodies and live-cell imaging:

  • Developing intracellular antibodies based on Di-Methyl-TP53 (K370) Antibody

  • This would enable real-time monitoring of p53 methylation in living cells