THRA Antibody

What is THRA and what types of THRA antibodies are available for research?

THRA (Thyroid Hormone Receptor, alpha) is a nuclear hormone receptor for triiodothyronine with a molecular weight of approximately 54.8 kDa . The canonical human protein consists of 490 amino acid residues and is localized in both the nucleus and cytoplasm . Multiple THRA antibody types are available:

• Polyclonal antibodies: Typically rabbit-derived, targeting different protein regions

• Monoclonal antibodies: Mouse-derived with specific epitope recognition

• Host variations: Available in rabbit, mouse, and other species

• Region-specific antibodies: Target N-terminal, middle region, or C-terminal domains

• Conjugated versions: Including HRP, alkaline phosphatase, FITC, biotin, and PE conjugates

The observed molecular weight of THRA in Western blot applications typically ranges between 50-58 kDa .

What are the primary research applications for THRA antibodies?

THRA antibodies are utilized across multiple experimental platforms:

THRA antibodies have been validated in multiple species including human, mouse, rat, and in some cases more diverse organisms such as zebrafish, cow, dog, horse, rabbit, sheep, and guinea pig .

How do THRA antibodies differ from TRAb (Thyrotropin Receptor Antibodies)?

This is a critical distinction for researchers:

• THRA antibodies: Laboratory reagents developed for research to detect thyroid hormone receptor alpha protein. These are tools for studying receptor expression, localization, and function .

• TRAb: Autoantibodies produced in patients with autoimmune thyroid disorders (particularly Graves' disease) that bind to the thyrotropin (TSH) receptor. TRAb exist as stimulating or blocking antibodies and are clinical biomarkers measured in diagnostic assays .

TRAb assays are primarily used in clinical settings for diagnosing Graves' disease, assessing relapse risk, or predicting neonatal thyrotoxicosis , while THRA antibodies are research tools with no direct clinical diagnostic utility.

What factors should be considered when selecting a THRA antibody for Western blot applications?

When selecting a THRA antibody for Western blot:

• Epitope location: Target preserved regions for cross-species studies; the middle region (amino acids 87-178) appears well-conserved across species

• Isoform specificity: Some antibodies (like PA1-211A) do not detect THRA-2 or THRB-1

• Dilution optimization: Typically 1:1000-1:4000, though sample-dependent

• Positive controls: A431 cells and mouse brain tissue are validated positive controls

• Expected bands: Prepare for potential double bands at ~58 kDa and ~50 kDa

• Cross-reactivity: Consider potential cross-reactivity with related nuclear receptors

Always titrate antibodies in each testing system to obtain optimal results based on your specific experimental conditions .

How can researchers validate the specificity of a THRA antibody?

Validation should follow a multi-faceted approach:

• Positive and negative tissue controls: Use tissues with known THRA expression patterns

• Knockdown/knockout validation: Test in THRA-depleted cells/tissues

• Peptide competition assays: Pre-incubation with immunizing peptide should abolish specific binding

• Multiple antibody approach: Use antibodies targeting different THRA epitopes

• Western blot analysis: Confirm detection of expected molecular weight bands (50-58 kDa)

• Purification method assessment: Consider whether the antibody underwent affinity purification

For polyclonal antibodies like ABIN2776019, validation on Western blot with the specific immunogen peptide confirms specificity for the middle region of THRA .

What storage and handling practices ensure optimal THRA antibody performance?

To maintain antibody integrity:

• Storage temperature: Store at -20°C for long-term stability

• Aliquoting: For 20μL sizes containing 0.1% BSA, aliquoting is unnecessary for -20°C storage

• Buffer composition: Typical storage buffers contain PBS with 0.02% sodium azide and 50% glycerol at pH 7.3

• Stability: Most preparations remain stable for one year after shipment when properly stored

• Working solutions: Avoid repeated freeze-thaw cycles by preparing single-use working dilutions

• Shipping conditions: Temporary exposure to ambient temperatures during shipping doesn't typically affect antibody performance

How can THRA antibodies be used to distinguish between THRA isoforms?

Distinguishing THRA isoforms requires strategic approaches:

• Isoform-specific antibodies: Choose antibodies like PA1-211A that recognize specific isoforms while excluding others (e.g., does not detect THRA-2)

• Molecular weight discrimination: THRA1 and THRA2 have distinct molecular weights that can be resolved on higher percentage gels

• Combination with transcript analysis: Complement protein detection with RT-PCR using isoform-specific primers

• Epitope mapping: Select antibodies targeting regions that differ between isoforms

• Recombinant standards: Use purified isoforms as positive controls

Up to four different isoforms have been reported for THRA , making careful antibody selection critical for isoform-specific studies.

What approaches can be used to study THRA-protein interactions?

For studying THRA-protein interactions:

• Co-immunoprecipitation: THRA antibodies can pull down receptor complexes for subsequent analysis

• Gel shift assays: Particularly valuable for studying THRA1 homodimers and THRA1/retinoic X receptor (RXR) heterodimers

• Chromatin immunoprecipitation: To study THRA DNA binding and associated proteins

• Proximity ligation assays: Visualize protein interactions in situ

• Mass spectrometry: Identify novel interaction partners after immunoprecipitation

Proper antibody selection is crucial—for example, products like PA1-211A have been successfully used in gel shift procedures to detect TR alpha-1 homodimers and TR alpha-1/RXR heterodimers .

How do THRA antibodies contribute to understanding thyroid hormone signaling in disease models?

THRA antibodies enable several key approaches:

• Expression analysis: Quantify receptor levels in disease tissues versus controls

• Cellular localization: Determine if receptor distribution changes in pathological states

• Post-translational modifications: Detect disease-associated alterations in receptor phosphorylation or other modifications

• Co-factor recruitment: Assess changes in receptor-associated proteins

• Cross-pathway interactions: Investigate altered nuclear receptor crosstalk

THRA has been specifically associated with hypothyroidism , making these antibodies valuable tools in understanding disease mechanisms.

What are common causes of non-specific binding with THRA antibodies?

When encountering non-specific binding:

• Antibody concentration: Excessive concentration increases background; titrate carefully (1:1000-1:4000 for WB)

• Blocking optimization: Insufficient blocking can increase background; optimize blocking conditions

• Sample preparation: Protein degradation may generate fragments recognized non-specifically

• Buffer composition: Adjust salt concentration, detergent levels, and pH to reduce non-specific interactions

• Incubation conditions: Temperature and time affect antibody specificity; follow recommended protocols

• Secondary antibody cross-reactivity: Use highly cross-adsorbed secondary antibodies

Each antibody should be titrated in specific testing systems to obtain optimal results, as indicated in product documentation .

How can researchers improve detection of low THRA expression levels?

To enhance sensitivity:

• Signal amplification: Consider enzyme-amplified detection systems

• Sample enrichment: Fractionate samples to concentrate nuclear proteins where THRA is primarily located

• Exposure optimization: Extended exposure times for Western blots or imaging

• Enhanced chemiluminescence: Use high-sensitivity substrates for WB applications

• Antibody concentration: Adjust within appropriate ranges while monitoring background

• Fresh reagents: Ensure antibodies haven't undergone degradation through improper storage

When working with tissues expressing low THRA levels, consider subcellular fractionation to concentrate nuclear proteins before Western blot analysis.

Why might THRA antibodies show different molecular weights than expected?

Variable molecular weights may result from:

• Post-translational modifications: Phosphorylation or other modifications alter migration patterns

• Isoform detection: Different THRA isoforms have distinct molecular weights

• Species differences: Human versus mouse THRA may migrate differently

• Gel concentration effects: Percentage of acrylamide affects protein migration

• Sample preparation: Incomplete denaturation may result in complexes or altered migration

The calculated molecular weight for human THRA is 54 kDa (490 amino acids), but observed Western blot bands typically appear at 58 kDa and 50 kDa , likely reflecting different isoforms or post-translational modifications.

How can THRA antibodies be applied in chromatin immunoprecipitation (ChIP) studies?

For successful ChIP applications:

• Fixation optimization: Typically 1% formaldehyde for 10 minutes at room temperature

• Sonication parameters: Optimize to generate 200-500bp DNA fragments

• Antibody selection: Choose ChIP-validated THRA antibodies

• Controls: Include IgG negative control and positive control loci

• Quantification methods: qPCR, ChIP-seq, or ChIP-chip for genome-wide binding profiles

• Sequential ChIP: To examine co-occupancy with other nuclear receptors

These approaches allow researchers to map THRA binding sites across the genome and understand its role in transcriptional regulation.

What considerations are important when developing multiplexed assays with THRA antibodies?

For multiplexed detection:

• Species compatibility: Choose primary antibodies from different host species

• Spectral separation: Select fluorophores with minimal spectral overlap

• Sequential staining: Consider sequential rather than simultaneous application

• Cross-reactivity testing: Validate antibody combinations for absence of cross-reactivity

• Controls: Include single-stain controls for accurate compensation/unmixing

• Optimization: Titrate each antibody individually before combining

Multiplexed approaches are particularly valuable for studying THRA interactions with other nuclear receptors or cofactors.

How does THRA antibody performance compare between different vertebrate species?

Cross-species reactivity considerations:

• Sequence conservation: The middle region sequence "DQIILLKGCC MEIMSLRAAV RYDPESDTLT LSGEMAVKRE QLKNGGLGVV" shows high conservation

• Validated reactivity: Some antibodies show confirmed reactivity across human, mouse, rat and chicken samples

• Predicted reactivity: Bioinformatic analysis predicts reactivity in cow, dog, guinea pig, horse, rabbit, rat, sheep, and zebrafish for some antibodies

• Epitope selection: Antibodies targeting highly conserved domains offer broader cross-species utility

• Validation requirements: Each new species application requires empirical validation

When working across species, select antibodies specifically validated or predicted to work in your species of interest.