hsp90ab1 Antibody

What is HSP90AB1 and why is it important in research?

HSP90AB1 (heat shock protein 90kDa alpha, class B member 1) is a molecular chaperone protein involved in various cellular processes including protein folding, maturation, activation, and degradation. It plays crucial roles in regulating signaling pathways for cell cycle progression, survival, and apoptosis . This protein interacts with numerous oncogenic client proteins, making it an important target for cancer research . HSP90AB1 has a calculated molecular weight of 723 amino acids (83 kDa) and an observed molecular weight of 83-90 kDa in experimental conditions . The protein is encoded by the gene with NCBI ID 3326 and has been shown to be highly expressed in various cancers .

What types of HSP90AB1 antibodies are available for research?

Research-grade HSP90AB1 antibodies fall into two main categories:

• Polyclonal antibodies: Such as the rabbit IgG polyclonal antibody (e.g., 11405-1-AP) which recognizes multiple epitopes of HSP90AB1 .

• Monoclonal antibodies: Including mouse-derived monoclonal antibodies like H90-10 (MIgG2a isotype) and recombinant monoclonal antibodies that offer higher specificity and reproducibility .

The choice between these depends on the application, with polyclonals sometimes offering higher sensitivity but monoclonals providing better specificity and consistency across experiments.

What are the validated applications for HSP90AB1 antibodies?

HSP90AB1 antibodies have been validated for multiple applications with specific recommended dilutions:

These applications have been validated across human, mouse, and rat samples, with cited reactivity in additional species including pig, chicken, sheep, and deer .

How should I design HSP90AB1 knockdown experiments to study its function in cancer models?

When designing HSP90AB1 knockdown experiments for cancer research, consider these methodological approaches:

• Lentiviral transfection over chemical inhibitors: Research demonstrates greater specificity by using lentiviral vectors for HSP90AB1 knockdown rather than HSP90 inhibitors, which allows excluding effects from other HSP90 subtypes .

• Validation through multiple assays: Successful knockdown protocols combine multiple functional assays:

  • Proliferation: CCK-8 assay, EdU incorporation assay, colony formation assay

  • Migration: Transwell migration assay, wound healing assay

  • In vivo validation: Nude mouse xenograft models

  • Molecular confirmation: Western blotting for protein expression changes

• Pathway analysis: Assess downstream effects on the PI3K-Akt-mTOR pathway, particularly phospho-Akt levels, as HSP90AB1 knockdown significantly reduces phospho-Akt without affecting total Akt levels .

• Glycolysis assessment: Measure both mRNA expression of glycolytic enzymes (HK2, PFKL, ALDOA, PGK1, ENO1, ENO2, PKM2, LDHA) and functional glycolytic parameters (ATP, pyruvate, lactic acid concentrations, and enzyme activities) .

What are the critical factors for optimizing HSP90AB1 antibody performance in immunohistochemistry?

For optimal IHC performance with HSP90AB1 antibodies, consider these technical factors:

• Antigen retrieval method: Published data indicates superior results using TE buffer pH 9.0 for heat-induced epitope retrieval, though citrate buffer pH 6.0 may be used as an alternative .

• Antibody dilution optimization: Begin with recommended ranges (1:250-1:1000 for polyclonal; 1:50-1:200 for monoclonal antibodies), then titrate in your specific tissue system .

• Tissue-specific considerations: HSP90AB1 antibodies have been validated on specific tissues including human pancreas cancer tissue, human breast cancer tissue, and human colon tissue .

• Positive controls: Include known positive samples such as tissues with high HSP90AB1 expression (cancer tissues) to validate staining patterns .

• Signal amplification: For tissues with lower expression levels, consider signal amplification systems while maintaining specificity through appropriate negative controls.

How can I effectively use HSP90AB1 antibodies for co-immunoprecipitation studies?

For successful co-immunoprecipitation (Co-IP) experiments with HSP90AB1 antibodies:

• Antibody selection: Choose antibodies validated for IP/Co-IP applications. Polyclonal antibodies (like 11405-1-AP) have demonstrated efficacy in Co-IP applications according to published literature .

• Protein complex preservation: Use gentle lysis buffers containing 1% NP-40 or 0.5% Triton X-100 to maintain protein-protein interactions.

• Antibody amount optimization: Start with 0.5-4.0 μg of antibody for 1.0-3.0 mg of total protein lysate as recommended .

• Pre-clearing lysates: Remove non-specific binding proteins by pre-clearing lysates with control IgG and protein A/G beads.

• Validated cell lines: NIH/3T3 cells have shown successful IP results with HSP90AB1 antibodies and can serve as positive controls .

• Interaction validation: Confirm interactions through reciprocal Co-IP and additional methods like proximity ligation assays to validate physiological relevance.

How can I distinguish between HSP90AB1 and other HSP90 isoforms in my research?

Distinguishing between HSP90 isoforms requires careful technical consideration:

• Antibody epitope selection: Choose antibodies raised against unique regions of HSP90AB1. The H90-10 monoclonal antibody has been epitope-mapped and recognizes specific regions of HSP90AB1 not shared with other isoforms .

• Molecular weight differentiation: HSP90AB1 shows an observed molecular weight of 83-90 kDa. Compare this with HSP90AA1 (inducible form, ~90 kDa) and other isoforms through careful SDS-PAGE resolution .

• Validation through knockout/knockdown: Use cells with verified HSP90AB1 knockdown as negative controls. Published studies have used lentiviral knockdown systems specifically targeting HSP90AB1 to confirm antibody specificity .

• Cross-reactivity assessment: Test antibodies against recombinant proteins of different HSP90 isoforms to confirm specificity before experimental use.

• Gene-specific approaches: Complement protein detection with gene-specific qPCR to differentiate between isoform expression levels.

What are common sources of variability in HSP90AB1 antibody experiments and how can they be addressed?

When troubleshooting variability in HSP90AB1 antibody experiments, consider:

• Antibody lot-to-lot variation: Particularly relevant for polyclonal antibodies. Maintain detailed records of antibody lots and consider purchasing larger quantities of validated lots for long-term studies.

• Cell line heterogeneity: Different cell lines show variable HSP90AB1 expression levels. Validated positive cell lines include PC-3, HEK-293, Jurkat, MCF-7, HeLa, and HepG2 cells .

• Post-translational modifications: HSP90AB1 undergoes various modifications affecting antibody recognition. Choose antibodies that account for relevant modifications in your experimental system.

• Sample preparation inconsistencies: Standardize lysis buffers and protocols. For cancer tissue samples, consider variations in tumor heterogeneity and microenvironment factors.

• Tissue-specific differences: HSP90AB1 expression varies across tissues. Validated positive tissues include mouse/rat brain, thymus, and heart tissues .

• Protocol variables: Standardize critical parameters including:

  • Antigen retrieval methods (TE buffer pH 9.0 recommended for IHC)

  • Blocking reagents (optimize to reduce background without masking epitopes)

  • Incubation times and temperatures

  • Detection systems

How should I interpret contradictory results between different HSP90AB1 antibody applications?

When facing contradictory results across different applications:

• Application-specific validation: Each application (WB, IHC, IF, etc.) requires distinct validation. An antibody performing well in WB might not perform equally in IHC due to differences in epitope accessibility and protein conformation.

• Epitope conformation considerations: Native protein structure in IF/IHC versus denatured protein in WB can affect epitope accessibility. The H90-10 monoclonal antibody's epitope has been mapped, which can help predict application performance .

• Controls assessment: Evaluate positive and negative controls for each application. Published studies using HSP90AB1 antibodies provide benchmarks for expected results in different applications .

• Orthogonal approach: Confirm key findings using alternative methods:

  • Combine protein detection with mRNA analysis

  • Use multiple antibodies targeting different epitopes

  • Employ genetic approaches (siRNA, CRISPR) to validate specificity

• Technical vs. biological variability: Distinguish between technical artifacts and genuine biological differences through replicate experiments and statistical analysis.

How can HSP90AB1 antibodies be used to investigate its role in cancer progression and metastasis?

HSP90AB1 antibodies provide valuable tools for cancer research through:

• Expression profiling: IHC studies using HSP90AB1 antibodies have established correlations between expression levels and clinical parameters:

  • T grade in head and neck squamous cell carcinoma

  • Lymph node metastasis

  • Patient prognosis and survival

• Signaling pathway investigation: Western blot analysis with HSP90AB1 antibodies has revealed its role in stabilizing phospho-Akt, thereby maintaining activation of the PI3K-Akt-mTOR pathway crucial for cancer progression .

• Metabolic reprogramming studies: HSP90AB1 knockdown studies monitored by antibody detection have demonstrated its role in cancer cell glycolysis, showing:

  • Reduced expression of key glycolytic enzymes

  • Decreased ATP, pyruvate, and lactic acid production

  • Reduced activity of hexokinase, pyruvate kinase, and lactate dehydrogenase

• Therapeutic target assessment: HSP90AB1 antibodies can monitor the efficacy of HSP90 inhibitors or HSP90AB1-targeted therapies in reducing protein stability of oncogenic clients.

What methodological approaches should I use to study HSP90AB1's role in the stabilization of oncogenic client proteins?

To investigate HSP90AB1's role in stabilizing oncogenic clients:

• Client protein identification: Use HSP90AB1 antibodies in Co-IP experiments followed by mass spectrometry to identify novel client proteins in your cancer model of interest.

• Protein stability assays: Following HSP90AB1 knockdown or inhibition, monitor client protein half-life through:

  • Cycloheximide chase assays with Western blot detection

  • Pulse-chase experiments for newly synthesized proteins

• Conformational status assessment: Investigate whether HSP90AB1 maintains client proteins in active conformations through:

  • Activity assays for kinase clients

  • Conformation-specific antibodies where available

• Post-translational modification analysis: Examine how HSP90AB1 inhibition affects client protein modifications, particularly focusing on phosphorylation status of proteins like Akt (Ser473) .

• In vivo validation: Use xenograft models with HSP90AB1 knockdown cells to confirm in vitro findings, monitoring both HSP90AB1 and client protein levels in tumor samples.

How can I optimize HSP90AB1 antibody-based detection in glycolysis and metabolism research?

For metabolic studies involving HSP90AB1:

• Multi-level analysis approach: Combine antibody-based protein detection with functional metabolic assays as demonstrated in published research:

  • Western blotting for HSP90AB1 and glycolytic enzymes

  • qRT-PCR for mRNA expression of glycolytic genes

  • Enzymatic assays for glycolytic activity

  • Metabolite measurements (ATP, pyruvate, lactate)

• Co-expression analysis: Bioinformatics analysis has revealed positive correlations between HSP90AB1 expression and key glycolytic enzymes including PGK1, ENO1, PKM, and LDHA . Validate these relationships in your model system through multiplexed antibody detection.

• Upstream regulator assessment: Use HSP90AB1 and phospho-Akt (Ser473) antibodies together to investigate the mechanism by which HSP90AB1 regulates glycolysis through the PI3K-Akt-mTOR pathway .

• Subcellular localization studies: Employ IF/ICC with HSP90AB1 antibodies to investigate potential co-localization with glycolytic enzymes or metabolic organelles under various stress conditions.

• Temporal dynamics: Design time-course experiments following HSP90AB1 inhibition to determine the sequence of events from HSP90AB1 inhibition to metabolic changes, using antibody detection at multiple timepoints.

What are the best practices for using HSP90AB1 antibodies in flow cytometry?

For optimal flow cytometry results with HSP90AB1 antibodies:

• Intracellular staining protocol: HSP90AB1 is primarily cytosolic, requiring permeabilization. Recommended protocols use 0.25 μg antibody per 10^6 cells in a 100 μl suspension for intracellular staining .

• Cell fixation optimization: Paraformaldehyde (2-4%) fixation followed by permeabilization with 0.1-0.5% saponin or Triton X-100 provides access to intracellular HSP90AB1.

• Validated positive controls: HeLa cells have been validated for flow cytometry with HSP90AB1 antibodies and can serve as positive controls .

• Antibody titration: Despite recommended dilutions (1:50-1:200 for monoclonal antibodies), each experimental system requires titration to determine optimal signal-to-noise ratio .

• Multi-parameter analysis: HSP90AB1 can be effectively combined with cell cycle markers or other intracellular proteins for comprehensive analysis of cell populations.

How can I effectively validate HSP90AB1 antibody specificity in my experimental system?

Comprehensive validation of HSP90AB1 antibody specificity should include:

• Genetic validation approaches:

  • Use cell lines with CRISPR/Cas9 knockout or siRNA knockdown of HSP90AB1

  • Published studies have established successful knockdown models in multiple cell lines

• Peptide competition: Pre-incubate antibody with immunizing peptide to confirm binding specificity.

• Multiple antibody comparison: Use antibodies targeting different epitopes of HSP90AB1 and compare detection patterns.

• Cross-species reactivity assessment: Test antibodies on samples from different species when working with animal models. HSP90AB1 antibodies have been validated for human, mouse, and rat samples .

• Recombinant protein controls: Use purified recombinant HSP90AB1 as a positive control in Western blot applications.

• Immunohistochemical pattern analysis: Compare staining patterns with published literature on HSP90AB1 expression in tissues of interest.