At2g33190 encodes a putative F-box protein in Arabidopsis thaliana, also annotated as AtFDB16. It belongs to the F-box family of proteins containing a domain of unknown function (DUF295) . The protein has 379 amino acids and is categorized as a putative F-box protein that likely functions in protein-protein interactions and ubiquitin-mediated protein degradation pathways .
Several monoclonal antibody combinations are available for At2g33190 protein detection, typically targeting different regions of the protein:
N-terminal antibodies (X-O49316-N): Target the N-terminus sequence
C-terminal antibodies (X-O49316-C): Target the C-terminus sequence
Middle region antibodies (X-O49316-M): Target non-terminus sequences
These antibodies are usually provided as combinations of individual monoclonal antibodies that recognize specific epitopes within these regions.
At2g33190 antibodies can be used in several experimental approaches:
Western blotting (WB) for protein expression analysis
Immunoprecipitation (IP) for protein-protein interaction studies
Chromatin immunoprecipitation (ChIP) for DNA-protein interaction studies
Immunocytochemistry/Immunofluorescence (ICC/IF) for cellular localization
The ELISA titer for these antibodies is typically around 10,000, corresponding to approximately 1 ng detection sensitivity on Western blots .
Validation should follow multiple steps:
Genetic validation: Compare signal between wild-type and knockout/knockdown lines
Peptide competition assay: Pre-incubate antibody with the immunizing peptide prior to use
Cross-reactivity assessment: Test against related F-box proteins
Expression correlation: Compare protein detection with known transcript levels
Multiple antibody approach: Use antibodies targeting different regions of the same protein
Remember that approximately 50% of commercial antibodies may not meet basic standards for characterization, making validation particularly important .
For rigorous experimental design, include:
Negative controls:
At2g33190 knockout/knockdown lines
Samples from non-plant organisms
Secondary antibody-only controls
Pre-immune serum controls
Positive controls:
Loading controls:
Optimization should be systematic:
Sample preparation:
Antibody dilution:
Blocking conditions:
Test different blocking agents (BSA, milk, commercial blockers)
Optimize blocking time and temperature
Detection methods:
Multiple bands could result from:
Post-translational modifications: F-box proteins often undergo phosphorylation, ubiquitination, or SUMOylation
Protein degradation: Sample preparation issues leading to protein breakdown
Splice variants: Alternative splicing producing different protein isoforms
Cross-reactivity: Antibody recognizing related F-box proteins
Non-specific binding: Particularly common with polyclonal antibodies
To address this, validate the specificity using knockout lines and peptide competition assays, and consider using antibodies targeting different regions of the protein to confirm the identity of specific bands .
Follow this systematic approach:
Antibody validation:
Confirm antibody activity using peptide ELISA
Test different antibody batches or sources
Protein extraction optimization:
Try different extraction buffers
Ensure protein is not denatured in a way that destroys the epitope
Check protein transfer efficiency
Signal enhancement strategies:
Expression verification:
To reduce background:
Blocking optimization:
Test different blocking agents (BSA, milk, commercial blockers)
Extend blocking time
Add blocking agent to antibody dilution buffer
Washing optimization:
Increase wash duration and frequency
Try different detergent concentrations (Tween-20, NP-40)
Antibody dilution:
Use higher dilutions of primary and secondary antibodies
Pre-absorb antibodies with plant extracts from knockout lines
Sample preparation:
For studying At2g33190 protein interactions:
Co-immunoprecipitation (Co-IP):
Proximity ligation assay (PLA):
Combine At2g33190 antibody with antibodies against potential interaction partners
Allows visualization of interactions in situ with subcellular resolution
Chromatin immunoprecipitation (ChIP):
For PTM analysis:
Modification-specific detection:
Run samples on Phos-tag gels to separate phosphorylated forms
Use 2D gel electrophoresis to separate by charge and mass
Perform immunoprecipitation followed by mass spectrometry
Treatment comparisons:
Compare samples treated with phosphatase inhibitors vs. phosphatases
Analyze samples from plants under different stress conditions
Compare wild-type vs. mutants in PTM pathways
Sequential immunoprecipitation:
For localization studies:
Immunohistochemistry protocols:
Fixation optimization for plant tissues (paraformaldehyde, glutaraldehyde)
Permeabilization methods compatible with plant cell walls
Antigen retrieval techniques if needed
Co-localization studies:
Use with organelle markers for subcellular localization
Combine with in situ hybridization for simultaneous protein/transcript detection
Developmental analysis:
Comparative considerations:
Cross-reactivity potential:
F-box domain conservation may lead to cross-recognition
Validate specificity against related F-box proteins
Choose antibodies targeting unique regions outside the F-box domain
Application differences:
Some F-box protein antibodies may work better in certain applications
Compare performance in Western blot vs. immunoprecipitation vs. immunofluorescence
Reference data:
Integration strategies:
Proteomics correlation:
Compare antibody-based quantification with mass spectrometry data
Validate protein-protein interactions identified by IP-MS with direct antibody detection
Transcriptomic integration:
Correlate protein levels (antibody detection) with transcript levels (RNA-seq)
Identify post-transcriptional regulation by comparing protein/RNA ratios
Phenotypic correlation:
When facing conflicting results:
Epitope differences:
Antibodies targeting different regions may give different results
Some epitopes may be masked by protein-protein interactions
Post-translational modifications may affect epitope recognition
Methodological validation:
Perform side-by-side comparisons using identical samples
Test both antibodies in knockout/knockdown lines
Consider if different fixation/extraction methods affect epitope availability
Confirmatory approaches:
Computational approaches:
Sequence-based prediction:
Epitope mapping:
Computational prediction of antibody binding sites
In silico modeling of antibody-antigen interactions
Validation of predictions with experimental epitope mapping
Cross-reactivity assessment:
Recent advances include:
High-throughput validation approaches:
Simultaneous testing against multiple related proteins
Microarray-based validation against proteome fragments
CRISPR knockout cell line panels for specificity testing
Standardization initiatives:
Research Identification Initiative (RRID) for antibody tracking
Independent validation by organizations like YCharOS
Journals requiring specific validation data for antibody-based studies
Alternative binding reagents:
| Recommended Validation Methods for At2g33190 Antibodies |
|---|
| Method |
| -------- |
| Genetic validation |
| Peptide competition |
| Orthogonal detection |
| Independent antibodies |
| Mass spectrometry |
Essential reporting elements:
Antibody details:
Vendor and catalog number
Research Resource Identifier (RRID)
Clone names for monoclonal antibodies
Host species and antibody type (monoclonal/polyclonal)
Target region (N-terminal, C-terminal, middle region)
Experimental conditions:
Antibody concentration (preferably in µg/ml rather than dilution)
Incubation conditions (time, temperature, buffer)
Blocking reagents and conditions
Detection methods and sensitivity
Validation evidence:
Batch consistency approaches:
Internal reference standards:
Maintain a reference sample set for testing new batches
Document batch-to-batch variation systematically
Consider creating a standard curve with recombinant protein
Lot testing protocol:
Test each new lot against previous lots
Document minimum required concentration for detection
Establish acceptance criteria for new batches
Long-term strategy:
Optimal handling procedures:
Storage conditions:
Follow manufacturer recommendations (typically -20°C)
Avoid repeated freeze-thaw cycles
Consider adding preservatives for working dilutions (0.01% sodium azide)
Aliquoting strategy:
Create single-use aliquots upon receipt
Document date and freeze-thaw cycle number
Store in non-frost-free freezers if possible
Quality control: