KEGG: ecc:c5316
STRING: 199310.c5316
The paeA Antibody is a polyclonal antibody developed against the paeA protein found in Escherichia coli. There are two primary variants targeting different E. coli strains: one for E. coli strain K12 (Entrez Gene ID: 948735) and another for E. coli O157:H7 (Entrez Gene ID: 913900, Gene Symbol: ytfL) . These antibodies are typically derived from rabbit hosts (IgG isotype) and demonstrate specificity for bacterial targets. The antibodies recognize recombinant paeA protein, which is used as the immunogen during production. The corresponding UniProt numbers are P0AE45 for E. coli K12 and P0AE47 for E. coli O157:H7 .
Based on product specifications, paeA Antibody is validated for two primary research applications:
Enzyme-Linked Immunosorbent Assay (ELISA): For quantitative detection of paeA protein in samples, allowing researchers to measure protein concentrations.
Western Blot (WB): For qualitative detection and confirmation of paeA protein presence, enabling visualization of the protein based on molecular weight .
The antibody is particularly useful in bacterial research focusing on E. coli strains, especially when studying protein expression, localization, and function of paeA. The polyclonal nature of these antibodies means they can recognize multiple epitopes on the target protein, potentially providing stronger signals in detection applications compared to monoclonal antibodies.
For maintaining optimal antibody activity and stability, paeA Antibody should be stored at either -20°C or -80°C, as indicated in the product specifications . Researchers should adhere to the following storage guidelines:
Avoid repeated freeze-thaw cycles as they can lead to denaturation and reduced antibody performance
Prepare small aliquots for working stocks to minimize freeze-thaw cycles
For short-term use, the antibody can typically be stored at 4°C for up to one week (verify with specific product documentation)
Protect from light exposure and contamination, which can affect antibody stability and function
Following these storage recommendations will help maintain the antibody's specificity and sensitivity throughout your research project.
The two main variants of paeA Antibody target different strains of E. coli with distinct characteristics:
| Feature | E. coli K12 paeA Antibody | E. coli O157:H7 paeA Antibody |
|---|---|---|
| UniProt Number | P0AE45 | P0AE47 |
| Entrez Gene ID | 948735 | 913900 |
| Gene Symbol | paeA | ytfL |
| Applications | ELISA, WB | ELISA, WB |
| Purification Method | Antigen Affinity purified | Protein A/G purified |
| Components | Includes 200μg antigens, 1ml pre-immune serum, purified antibodies | Includes 200μg recombinant immunogen, 1ml pre-immune serum, purified antibodies |
| Research Focus | Laboratory strain (basic molecular biology) | Pathogenic strain (virulence studies) |
The key differences lie in their target specificity . The K12 variant targets the laboratory strain commonly used in molecular biology research, while the O157:H7 variant targets a pathogenic strain associated with foodborne illness. This distinction is crucial when designing experiments:
For basic molecular biology research: The K12 variant is typically more appropriate
For pathogenicity studies or detection of virulent strains: The O157:H7 variant would be preferred
The different purification methods may also affect antibody performance. Antigen-affinity purified antibodies often have higher specificity for the target antigen, while Protein A/G purification selects for all IgG antibodies in the serum .
Recommended validation protocols for paeA Antibody in Western Blot applications include:
Positive Control Validation:
Negative Control Validation:
Protocol Optimization:
Test multiple antibody dilutions (typically starting with manufacturer recommendations)
Optimize blocking conditions to reduce background
Test different detection systems (chemiluminescent vs. chromogenic)
Adjust exposure times to achieve optimal signal-to-noise ratio
Specificity Confirmation:
Perform peptide competition assay using the immunizing peptide
Conduct side-by-side comparison with alternative antibodies against the same target
Consider mass spectrometry validation of the detected band
Reproducibility Assessment:
Perform technical replicates
Test across multiple antibody lots if available
Validate results across different sample preparation methods
For optimal results, standard Western Blot protocols should be followed, with particular attention to appropriate sample preparation for bacterial proteins, which may require specialized lysis buffers to efficiently extract bacterial proteins.
Optimizing ELISA protocols with paeA Antibody involves several key considerations:
Antibody Titration:
Determine optimal primary antibody concentration through serial dilutions
Test concentrations ranging from 1:500 to 1:10,000 depending on antibody potency
Identify the dilution that provides maximum specific signal with minimal background
Format Selection:
Direct ELISA: Coat plates with sample containing paeA
Sandwich ELISA: Use a capture antibody against paeA, then detect with paeA Antibody
Competitive ELISA: Pre-incubate paeA Antibody with free antigen before adding to plate
Buffer Optimization:
Test different coating buffers (carbonate/bicarbonate pH 9.6 vs. PBS pH 7.4)
Optimize blocking solutions (BSA vs. non-fat milk vs. commercial blockers)
Evaluate different wash buffer compositions (PBS-T vs. TBS-T)
Incubation Parameters:
Compare different incubation temperatures (4°C, room temperature, 37°C)
Test various incubation times for antibody binding
Evaluate plate shaking vs. static incubation
Detection System:
Select appropriate enzyme-conjugated secondary antibody (HRP or AP)
Choose optimal substrate (TMB, ABTS, pNPP) based on sensitivity requirements
Consider amplification systems for low-abundance targets
When working with bacterial targets like paeA, particular attention should be paid to sample preparation methods that effectively solubilize the target protein without introducing interfering substances.
Computational models like PARA (Pre-trained model of Antibody sequences trained with a Rational Approach for antibodies) can be valuable tools for predicting antibody-antigen interactions and optimizing antibody applications:
Sequence-Based Predictions:
Use PARA to analyze the antibody's complementarity-determining regions (CDRs)
Predict potential binding epitopes on paeA protein
Estimate binding affinity based on sequence characteristics
Structural Modeling Applications:
Generate 3D models of antibody-antigen complexes
Identify critical residues involved in binding
Predict effects of mutations in either antibody or antigen
Cross-Reactivity Assessment:
Compare potential epitopes across related bacterial proteins
Identify regions of high similarity that might lead to cross-reactivity
Predict off-target binding based on structural similarity
Implementation Approach:
Extract antibody sequence information from the product data
Input sequences into PARA or similar computational platforms
Run prediction algorithms for binding properties
Validate computational predictions experimentally
As described in research, PARA employs "a strategy conforming to antibody sequence patterns and an advanced natural language processing self-encoding model structure" . This approach can capture the unique features of antibody sequences better than general protein modeling tools, making it particularly valuable for predicting paeA Antibody properties and optimizing experimental protocols.
When facing inconsistent results with paeA Antibody, researchers can employ systematic troubleshooting approaches:
Antibody Validation:
Sample Preparation Analysis:
Compare different bacterial lysis methods (sonication, bead-beating, chemical lysis)
Assess the impact of different buffer compositions on antigen integrity
Evaluate the effects of sample storage conditions and freeze-thaw cycles
Protocol Standardization:
Develop detailed standard operating procedures (SOPs)
Control for variables like temperature, incubation time, and reagent concentrations
Implement internal controls for normalization across experiments
Interference Identification:
Test for matrix effects in complex samples
Evaluate potential inhibitors present in different sample types
Consider pre-clearing samples to remove interfering substances
Multi-Method Verification:
Confirm results using alternative detection methods
Combine Western blot with ELISA or other techniques
Use orthogonal approaches (e.g., mass spectrometry) to verify target identity
This systematic approach allows researchers to identify the source of inconsistencies and develop strategies to obtain reliable, reproducible results when working with paeA Antibody across different experimental setups.
Integrating paeA Antibody research with computational antibody sequence analysis offers powerful opportunities for enhanced understanding and application:
Epitope Mapping and Prediction:
Use computational tools to predict antibody binding sites on paeA
Employ algorithms that analyze both linear and conformational epitopes
Integrate experimental epitope mapping data with computational predictions
Structural Analysis:
Generate antibody-antigen complex models using AlphaFold or similar tools
Predict binding energetics and stability of interactions
Visualize binding interfaces to understand molecular recognition
Sequence-Structure-Function Relationships:
Correlate antibody sequence variations with functional differences
Apply machine learning to predict binding properties based on sequence features
Identify critical residues for antibody-antigen interactions
Implementation Strategy:
Start with sequence analysis of the paeA protein to identify potential epitopes
Use PARA or similar models to predict antibody binding characteristics
Compare predictions with experimental results
Refine models based on experimental feedback
As modern antibody research increasingly incorporates computational approaches, researchers can leverage tools like PARA that employ "a strategy conforming to antibody sequence patterns and an advanced natural language processing self-encoding model structure" . This integration creates a powerful framework for advancing antibody research beyond traditional methods.
Implementing paeA Antibody in multiplex immunoassays requires careful methodological planning:
Compatibility Assessment:
Evaluate buffer compatibility across multiple antibodies
Test for potential cross-reactivity between antibodies
Assess shared secondary antibody requirements
Optimization of Antibody Panels:
Determine optimal concentrations for each antibody in the multiplex
Balance signal intensities across different targets
Consider using antibodies from different host species to enable distinct detection
Cross-Reactivity Mitigation:
Perform single-plex controls alongside multiplex assays
Include absorption controls to verify specificity
Consider using monoclonal antibodies for critical targets
Detection System Selection:
Choose detection systems with minimal spectral overlap
Consider fluorescent labels with distinct excitation/emission profiles
Evaluate quantum dots or other advanced labels for improved separation
Validation Strategy:
Compare multiplex results with single-plex assays
Assess precision across replicates and runs
Determine limits of detection for each analyte in the multiplex context
When incorporating paeA Antibody into multiplex assays, researchers should first validate it in single-plex format and then gradually incorporate additional targets, carefully monitoring for any interference or cross-reactivity issues. This stepwise approach helps ensure reliable results in the more complex multiplex setting.
Cross-reactivity is an important consideration when working with antibodies against bacterial proteins like paeA:
Strain-Specific Considerations:
Species Cross-Reactivity:
While the antibody is validated for bacteria, specific reactivity beyond E. coli may vary
Check for potential cross-reactivity with related Enterobacteriaceae family members
Sequence alignment of paeA homologs across bacterial species can help predict potential cross-reactions
Non-Specific Binding:
The polyclonal nature of the antibody means multiple epitopes are recognized, potentially increasing non-specific binding
Optimize blocking conditions to minimize background
Consider additional purification steps if high specificity is required
Validation Approaches:
Western blot analysis against lysates from multiple bacterial species
ELISA against purified proteins from related bacteria
Pre-adsorption experiments to remove cross-reactive antibodies
Competition assays with homologous proteins
Experimental Controls:
Include genetically modified strains lacking paeA as negative controls
Use purified recombinant proteins from related bacteria as specificity controls
Consider multiple detection methods to confirm specificity
Understanding the potential cross-reactivity profile helps researchers interpret results accurately and design appropriate controls to validate antibody specificity in their specific experimental context.