TP53 (Ab-6) Antibody

What is TP53 (Ab-6) Antibody and what epitope does it recognize?

TP53 (Ab-6) Antibody, also known as DO-1 mouse monoclonal antibody, is a pantropic antibody that recognizes an epitope mapped to amino acids 21-25 of human p53 protein. This antibody has been validated for detecting wild-type and many mutant forms of p53 protein across multiple species, predominantly human (H) and feline (Fe) . The antibody is derived from mouse (M) as the host organism and functions as a pantropic antibody, meaning it can detect various forms of p53 regardless of conformational changes associated with common mutations .

What are the validated applications for TP53 (Ab-6) Antibody?

The TP53 (Ab-6) Antibody has been validated for multiple experimental applications in research settings:

This versatility makes it a valuable tool for researchers investigating p53 expression and function in various experimental contexts .

What is the relationship between TP53 mutations and antibody detection?

TP53 mutations, particularly missense mutations, often lead to stabilization and accumulation of the mutant p53 protein in tumor cells. While TP53 (Ab-6) Antibody can detect this accumulated protein, there is an important distinction between detecting the protein and identifying specific mutations. Studies have shown that when p53 antibodies detect accumulated p53 in tumors, there is approximately a 30% sensitivity for detecting underlying TP53 gene mutations . This means that while positive antibody staining suggests p53 dysfunction, not all mutations will result in detectable protein accumulation, and conversely, protein accumulation can occasionally occur without mutations . Researchers should therefore consider complementary genetic approaches when definitive mutation identification is required.

How can TP53 (Ab-6) Antibody be used to distinguish between different p53 functional states?

While TP53 (Ab-6) Antibody detects total p53 protein regardless of functional state, advanced research applications can combine this antibody with other analytical techniques to distinguish between different p53 functional states. For example, co-immunoprecipitation using TP53 (Ab-6) followed by analysis of post-translational modifications (phosphorylation, acetylation, ubiquitination) can reveal activation status. When p53 functions as a transcription factor, it undergoes specific post-translational modifications and forms complexes with co-factors that can be detected after immunoprecipitation with TP53 (Ab-6) .

For truncating mutations specifically in exon-6 of the TP53 gene, studies have shown that the resulting proteins lack canonical p53 tumor suppressor functions while potentially gaining oncogenic properties . In these cases, TP53 (Ab-6) can still detect the truncated protein (as it binds to the N-terminus), but functional analysis requires assessment of downstream p53 target genes or cellular phenotypes such as EMT marker expression, which showed significant upregulation (p<0.05) in cells expressing specific truncation mutants like R196* and R213* .

What are the considerations when using TP53 (Ab-6) Antibody to study p53 neoantigen presentation?

When studying p53 neoantigen presentation, several advanced considerations apply when using TP53 (Ab-6) Antibody:

The antibody recognizes an N-terminal epitope of p53, which is distinct from the peptides typically presented as neoantigens on MHC/HLA molecules. For studies focused on specific mutations like R175H (arginine at position 175 replaced with histidine), specialized antibodies that recognize the mutant-specific epitope in complex with HLA molecules are preferred over general p53 antibodies like TP53 (Ab-6) .

Research has demonstrated that despite extremely low p53 peptide-HLA complex density on cancer cell surfaces, bispecific antibodies targeting specific p53 mutations (such as R175H) can effectively activate T cells to lyse cancer cells presenting these neoantigens . This suggests that for neoantigen-targeted immunotherapy approaches, mutation-specific antibodies may have advantages over pantropic antibodies like TP53 (Ab-6) .

How does truncation of p53 in exon-6 affect antibody recognition and protein function?

Truncation mutations in exon-6 of the TP53 gene produce unique proteins with distinct biological properties that can be detected with N-terminal antibodies like TP53 (Ab-6). Research has demonstrated that these truncated proteins:

• Lack canonical p53 tumor suppressor capabilities, as demonstrated by cell viability assays showing no growth suppression compared to wild-type p53 (p<0.0005)

• Retain expression at levels comparable to wild-type p53 in multiple tumor samples analyzed through TCGA datasets

• Display gain-of-function properties including promotion of epithelial-to-mesenchymal transition (EMT), as evidenced by:

  • Altered cell morphology with stress fiber formation

  • Decreased E-cadherin expression and altered localization

  • Upregulation of EMT markers (quantified by RT-qPCR)

  • Enhanced cell motility in wound-healing assays (p<0.0005)

For researchers studying these truncation mutants, TP53 (Ab-6) Antibody remains valuable for detection, but functional studies require assessing downstream effects rather than just protein presence .

What is the significance of serum p53 antibodies in cancer patients and how do they relate to TP53 (Ab-6) Antibody detection?

While TP53 (Ab-6) is a laboratory reagent for detecting p53 protein, patients with cancer can develop autoantibodies against their own p53 protein, particularly when it contains mutations. These autoantibodies have significant clinical and research implications:

Studies have demonstrated that p53 autoantibodies are found predominantly in cancer patients with a specificity of approximately 96%, making them highly specific biomarkers . These autoantibodies are primarily associated with missense mutations in the TP53 gene and consequent p53 protein accumulation in tumors, although the sensitivity for detecting such mutations is only around 30% .

Researchers investigating p53 autoantibodies in patient sera should note that these autoantibodies recognize predominantly conformational epitopes on mutant p53, which differ from the linear epitope recognized by TP53 (Ab-6) Antibody .

What are the optimal conditions for using TP53 (Ab-6) Antibody in different applications?

When using TP53 (Ab-6) Antibody across different experimental applications, researchers should consider these optimized parameters:

For Western Blotting:

• Sample preparation: Complete lysis buffers containing protease inhibitors are essential to prevent p53 degradation

• Protein loading: 20-50 μg of total protein per lane is typically sufficient

• Blocking: 5% non-fat milk or BSA in TBST for 1 hour at room temperature

• Primary antibody dilution: 1:500 to 1:1000 dilution is typically effective

• Incubation: Overnight at 4°C provides optimal signal-to-noise ratio

• Detection: Both chemiluminescence and fluorescence-based systems are suitable

For Immunohistochemistry:

• Antigen retrieval: Heat-induced epitope retrieval in citrate buffer (pH 6.0) is recommended

• Blocking: Endogenous peroxidase blocking followed by protein blocking

• Antibody dilution: 1:50 to 1:200 depending on tissue type and fixation

• Counterstaining: Hematoxylin provides good nuclear contrast to evaluate p53 nuclear localization

These conditions should be optimized for each specific experimental context and tissue/cell type being studied.

How can researchers distinguish between wild-type and mutant p53 when using TP53 (Ab-6) Antibody?

Since TP53 (Ab-6) Antibody is pantropic and recognizes both wild-type and mutant p53 proteins, researchers must employ additional techniques to distinguish between them:

• Expression pattern analysis: Wild-type p53 is typically expressed at low levels in normal tissues with minimal antibody staining, while mutant p53 often shows strong nuclear accumulation in tumor cells

• Complementary mutation-specific antibodies: For common mutations like R175H, researchers can use mutation-specific antibodies alongside TP53 (Ab-6) for comparative analysis

• Functional assays: Following detection with TP53 (Ab-6), researchers can assess:

  • DNA binding capacity (wild-type p53 binds target sequences while many mutants do not)

  • Transcriptional activity using p53-responsive reporter constructs

  • Expression analysis of downstream p53 target genes (p21, MDM2, PUMA)

• Genetic analysis: Complementing TP53 (Ab-6) immunodetection with DNA sequencing of the TP53 gene provides definitive mutation status

These approaches allow researchers to contextualize TP53 (Ab-6) Antibody results within the functional status of p53 in their experimental systems.

What controls should be included when using TP53 (Ab-6) Antibody in experimental designs?

Robust experimental design with appropriate controls is essential when using TP53 (Ab-6) Antibody:

Positive Controls:

• Cell lines with known p53 status: A549 (wild-type p53, high expression), MCF-7 (wild-type p53)

• Cell lines with known p53 mutations: SW684 (exon-6 truncating mutation), Calu-6 (p53 mutation)

• Recombinant full-length p53 protein (for Western blot standards)

Negative Controls:

• p53-null cell lines: H1299 cells (complete absence of p53 expression)

• Isotype control antibody (matching the primary antibody's host species and isotype)

• Primary antibody omission controls

Validation Controls:

• siRNA/shRNA knockdown of p53 to confirm antibody specificity

• Competing peptide controls using the epitope recognized by the antibody

• Multiple detection methods (e.g., Western blot confirmation of IHC findings)

Studies have demonstrated the specificity of these controls, with clear differentiation between p53-expressing and p53-null cell lines when probed with N-terminal antibodies like DO1 .

How can TP53 (Ab-6) Antibody be used in cancer diagnostic and prognostic research?

TP53 (Ab-6) Antibody has valuable applications in cancer diagnostic and prognostic research:

For Diagnostics:

• Detection of p53 protein accumulation in tumor samples, which has been associated with TP53 mutations in many cancer types

• Complementary approach to genetic testing, particularly in settings where sequencing is not readily available

• Screening tool for identifying samples that may require further genetic analysis

For Prognostics:

• Multiple studies have demonstrated associations between p53 immunopositivity and clinical outcomes

• In a meta-analysis of cancer studies, p53 antibody detection showed strong correlation with tumor grade and patient survival in specific cancer types including breast, colon, oral, and gastric cancers

• Combination with other biomarkers can enhance prognostic value, as illustrated in a workflow for prediction of cancer survival outcomes

Research applications should consider that while p53 immunopositivity correlates with mutations, the sensitivity is approximately 30%, meaning that negative immunostaining does not rule out TP53 mutations .

What are the considerations when using TP53 (Ab-6) Antibody in studies of p53-targeted cancer therapies?

When using TP53 (Ab-6) Antibody in studies of p53-targeted cancer therapies, researchers should consider:

How can TP53 (Ab-6) Antibody contribute to understanding p53 gain-of-function mutations?

TP53 (Ab-6) Antibody can significantly contribute to research on p53 gain-of-function (GOF) mutations through several approaches:

• Protein Expression Quantification: GOF mutant p53 proteins typically accumulate to high levels in tumor cells, which TP53 (Ab-6) can detect and quantify via Western blotting or immunohistochemistry

• Protein Interaction Studies: Immunoprecipitation with TP53 (Ab-6) followed by mass spectrometry can identify novel protein interactions specific to GOF mutants

• Cellular Localization: While wild-type p53 shows predominantly nuclear localization, some GOF mutants exhibit altered subcellular distribution that can be visualized using TP53 (Ab-6) in immunofluorescence studies

• Truncation Mutant Analysis: Research utilizing TP53 (Ab-6) has demonstrated that exon-6 truncating mutations (R196* and R213*) produce proteins that:

  • Lack tumor suppressor capabilities

  • Promote epithelial-to-mesenchymal transition

  • Enhance cell motility (quantified in wound-healing assays with p<0.0005)

  • Alter expression of EMT markers including vimentin, ZEB1, and Snail (with statistically significant changes, p<0.05)

These applications highlight how TP53 (Ab-6) Antibody can be integrated into comprehensive research strategies investigating the complex biology of GOF p53 mutations.

What are the key considerations for researchers selecting TP53 (Ab-6) Antibody for their studies?

Researchers considering TP53 (Ab-6) Antibody for their studies should evaluate several key factors:

• Research Question Alignment: Determine whether a pantropic antibody that detects both wild-type and mutant p53 is appropriate for your specific research questions

• Application Compatibility: Confirm the antibody's validation status for your intended applications (Western blot, IHC, IP, etc.)

• Epitope Accessibility: Consider whether the N-terminal epitope recognized by TP53 (Ab-6) will be accessible in your experimental conditions, particularly for fixed tissues or complex protein interactions

• Complementary Approaches: Plan for additional techniques that will complement antibody detection, such as genetic analysis or functional assays, especially when distinguishing between wild-type and mutant p53 is critical

• Appropriate Controls: Ensure availability of suitable positive and negative controls to validate findings

• Interpretation Context: Recognize that p53 detection with TP53 (Ab-6) provides information about protein presence and levels but requires additional approaches to determine functional status