ENGASE2 is a glycoside hydrolase enzyme belonging to the GH18 and GH85 families. It hydrolyzes the β1-4 linkage of the N,N-diacetylchitobiose (GlcNAcβ1-4GlcNAc) region in N-linked glycans on glycoproteins . In Arabidopsis thaliana, ENGASE2 is implicated in cell wall modification and stress responses .
In Arabidopsis thaliana, ENGASE2 is linked to stress responses and cell wall integrity. Antibodies like CSB-PA798051XA01DOA enable localization studies to understand its role during pathogen attacks .
Human ENGASE antibodies (e.g., 31784-1-AP) are used to study glycan remodeling in cancer and immune regulation. Proteintech’s antibody has been applied in IF to visualize ENGASE distribution in HEK293 cells .
ENGASE2 antibodies are validated using:
IHC: Paraffin-embedded tissue sections with antigen retrieval .
IF: Fixed cells stained with fluorophore-conjugated secondary antibodies .
WB: Lysates from tissues with high ENGASE expression (e.g., spleen) .
Current ENGASE2 antibodies are species-specific, limiting cross-kingdom studies.
No clinical trials or therapeutic uses are reported, unlike antibodies targeting viral proteins (e.g., anti-ACE2 IgG in COVID-19) .
ENGASE2 antibodies are pivotal for dissecting glycosylation mechanisms in plants and humans. While existing products are robust for research, advancements in antibody engineering could expand their therapeutic potential.
STRING: 3702.AT3G11040.1
ENGASE2 Antibody functions similarly to other targeted antibodies by binding to specific epitopes with high specificity. Like antibodies targeting ACE2, the binding mechanism involves recognition of specific protein domains that can be detected through various assay systems. The binding functionality can be visualized through techniques such as western blotting, ELISA, immunofluorescence tests, and immunohistochemistry, which are commonly incorporated into diagnostic techniques for detecting antigens or antibodies against specific targets .
When designing experiments with ENGASE2 Antibody, researchers should consider the membrane pre-coating methodology similar to neutralizing antibody tests where the membrane is pre-coated with the target protein on the test line region. During testing, the specimen reacts with conjugated colloid gold, and the mixture migrates upward on the membrane chromatographically by capillary action to generate observable results .
Validation of ENGASE2 Antibody specificity requires a multi-step approach to ensure experimental reliability:
Cross-reactivity testing: Test the antibody against closely related protein targets to confirm specific binding to the intended target.
Western blot analysis: Verify that the antibody detects bands of the expected molecular weight.
Immunoprecipitation: Confirm the antibody can pull down the target protein from complex mixtures.
Knockout/knockdown controls: Use samples where the target protein is absent or depleted to confirm specificity.
Similar to approaches used in antibody specificity design, researchers should identify different binding modes associated with particular ligands against which the antibodies are either selected or not selected. This approach allows for disentangling binding modes even when they are associated with chemically similar ligands . Additionally, researchers should validate through experimental testing any computational predictions of antibody specificity to ensure reliable results.
To maintain optimal activity of ENGASE2 Antibody:
Temperature: Store at -20°C for long-term storage and 4°C for short-term (1-2 weeks) use.
Aliquoting: Divide into small single-use aliquots before freezing to avoid repeated freeze-thaw cycles.
Buffer composition: Store in phosphate-buffered saline (PBS) with a stabilizing protein (0.1-1% BSA or gelatin) and preservative (0.02% sodium azide).
Avoid freeze-thaw cycles: Each freeze-thaw cycle can reduce antibody activity by approximately 10-15%.
Validation of activity should be performed periodically, especially when using antibodies from stored stocks, by running positive controls alongside experimental samples to confirm retained functionality.
Optimization of ENGASE2 Antibody concentration requires a systematic titration approach with consideration of signal-to-noise ratio:
Titration matrix: Perform a checkerboard titration using varying antibody concentrations (typically 0.1-10 μg/mL) against known positive and negative controls.
Signal quantification: For each concentration, calculate the signal-to-noise ratio by dividing the positive signal by the background signal.
Blocking optimization: Test multiple blocking agents (BSA, milk proteins, commercial blockers) to identify which provides the lowest background with your antibody.
Similar to other antibody-based detection systems, sample volume is critical for optimal results. As seen in neutralizing antibody tests, specific volumes (e.g., 25 μL for IgG detection and 50 μL for neutralizing antibody detection) produce optimal results . For ENGASE2 Antibody, a preliminary titration series should identify the optimal combination of antibody concentration and sample volume that maximizes specific signal while minimizing background interference.
When analyzing ENGASE2 Antibody binding across multiple experimental conditions, the statistical approach should be carefully selected based on the experimental design:
For comparing multiple techniques with the same antibody preparation:
Friedman's test: This non-parametric equivalent of two-way ANOVA is appropriate when comparing ordinal data across multiple techniques, particularly when the same antibodies are tested across different methods. This test effectively separates variability due to techniques from that due to antibodies .
Wilcoxon's matched-pairs signed-rank test: For pairwise comparisons between techniques, this test uses both the sign and magnitude of differences between paired observations .
For comparing antibody performance across independent samples:
Kruskall-Wallis test: When comparing unpaired data across multiple groups, this non-parametric test is appropriate for ordinal data.
Mann-Whitney U test (Wilcoxon's two-sample test): For pairwise comparisons between independent samples .
Table 1: Comparison of Statistical Tests for Antibody Binding Data Analysis
| Test | Application | Data Requirements | Sensitivity | Comments |
|---|---|---|---|---|
| Friedman's Test | Multiple techniques, matched samples | Ordinal data, no missing values | High | Separates variability due to techniques from that due to antibodies |
| Wilcoxon Matched-Pairs | Pairwise comparison, matched samples | Ordinal data | Medium | Considers magnitude of differences |
| Kruskall-Wallis | Multiple groups, independent samples | Ordinal data | Medium | Appropriate when samples are not matched |
| Mann-Whitney U | Pairwise comparison, independent samples | Ordinal data | Medium | Less powerful than matched tests |
Development of ENGASE2 Antibody variants with enhanced specificity requires a combination of computational modeling and experimental validation:
Biophysics-informed modeling: Train models on experimentally selected antibodies and associate distinct binding modes with each potential ligand or epitope. This approach enables prediction and generation of specific variants beyond those observed in experiments .
Directed evolution: Design phage display experiments selecting antibodies against various combinations of ligands to provide training data for computational models .
Computational optimization: Generate new sequences by optimizing energy functions associated with each binding mode:
Experimental validation: Test computationally designed variants to confirm predicted specificity profiles.
This approach has demonstrated success in creating antibodies with both specific and cross-specific binding properties, even when target epitopes are chemically very similar . The combination of biophysics-informed modeling with extensive selection experiments provides a powerful toolset for designing antibodies with precisely tailored binding properties.
When facing contradictory results between different detection methods:
Systematic method comparison: Use a matched design where the same samples are tested with all methods. This allows separation of variability due to techniques from that due to samples .
Statistical evaluation: Apply Friedman's test to evaluate the significance of differences between methods, followed by pairwise comparisons using Wilcoxon's matched-pairs signed-rank test to identify which specific methods differ significantly .
Method validation assessment: Evaluate each method for:
Analytical sensitivity (limit of detection)
Analytical specificity (cross-reactivity)
Reproducibility (inter-assay and intra-assay variation)
Matrix effects (interference from sample components)
Confirmatory testing: Use an orthogonal method (e.g., mass spectrometry) as a reference standard when antibody-based methods produce conflicting results.
The resolution of contradictory results should consider the specific strengths and limitations of each method. For example, ELISA may provide higher sensitivity but lower specificity compared to western blotting, while immunohistochemistry offers spatial information but may be affected by epitope masking during fixation.
Based on studies of autoantibodies against similar targets, several factors may influence the prevalence of autoantibodies that could cross-react with ENGASE2 Antibody targets:
Disease state: Certain infectious or autoimmune conditions may trigger autoantibody production. For example, studies on ACE2 autoantibodies in SARS-CoV-2 infected patients revealed a prevalence of 1.5% with most being male patients (76.5%) .
Disease severity: Patients with severe infections showed twofold higher titers of autoantibodies than mild cases, suggesting disease intensity correlates with autoantibody production .
Sex differences: Significant sex-based differences in autoantibody prevalence have been observed, with studies showing higher prevalence in males for certain autoantibodies .
To control for potential autoantibody interference:
Pre-absorption: Include a pre-absorption step with purified target antigen to compete away specific binding.
Negative controls: Include age and sex-matched control samples without the disease of interest.
Epitope mapping: Identify epitopes recognized by autoantibodies versus those targeted by ENGASE2 Antibody to assess potential overlap.
Competitive assays: Use competitive binding assays to differentiate between specific antibody binding and autoantibody interference.
Distinguishing specific binding from non-specific interactions requires multiple control strategies:
Isotype controls: Include matched isotype controls at the same concentration as the ENGASE2 Antibody to assess non-specific binding.
Blocking optimization: Systematically test different blocking agents (BSA, casein, commercial blockers) and concentrations to minimize background while preserving specific signal.
Pre-adsorption controls: Pre-incubate the antibody with purified target antigen before applying to samples. Specific binding should be eliminated while non-specific binding remains.
Knockout/knockdown controls: Use samples where the target is genetically depleted or absent as negative controls.
Signal amplification assessment: When using amplification methods, include controls without the primary antibody to assess contribution of the detection system to background.
Titration analysis: Perform antibody titrations to identify the concentration that provides optimal signal-to-noise ratio. True specific binding should decrease proportionally with antibody dilution, while non-specific binding often has different dilution dynamics.
Epitope selection is a critical determinant of antibody cross-reactivity profiles:
Conserved vs. unique domains: Epitopes in highly conserved regions of protein families will lead to broader cross-reactivity, while epitopes in divergent regions provide greater specificity.
Structural accessibility: Surface-exposed epitopes are more accessible but may be less specific, while buried epitopes may offer higher specificity but reduced accessibility in native proteins.
Post-translational modifications: Epitopes containing or adjacent to sites of glycosylation, phosphorylation, or other modifications may exhibit variable recognition depending on the modification state.
Using biophysics-informed models for antibody design, researchers can identify and disentangle multiple binding modes associated with specific epitopes. This approach enables the prediction and generation of antibody variants with customized specificity profiles . By analyzing the energy functions associated with binding to different epitopes, researchers can design antibodies that either discriminate between highly similar epitopes or recognize conserved epitopes across protein families, depending on the experimental goals.
Minimizing cross-reactivity in multiplex assays requires comprehensive planning:
Sequential epitope mapping: Systematically map epitopes recognized by the antibody against a panel of related proteins to identify potential cross-reactivity.
Computational design: Employ biophysics-informed models to design antibody variants with customized specificity profiles that minimize binding to undesired targets .
Buffer optimization: Test various buffer compositions to minimize non-specific interactions:
Detergent type and concentration
Salt concentration
pH optimization
Blockers and carriers
Absorption pre-treatment: Pre-absorb samples with recombinant proteins or peptides representing potential cross-reactive targets.
Spike-in controls: Include known quantities of potential cross-reactive proteins to quantify the degree of cross-reactivity under assay conditions.
Detection system optimization: When using secondary antibodies or detection reagents, ensure they don't contribute to cross-reactivity by testing their specificity independently.
Data analysis: Apply mathematical corrections and statistical approaches to account for known cross-reactivity patterns in multiplex data.
Optimization for immunohistochemistry applications requires consideration of multiple parameters:
Fixation method:
Formalin fixation: May require antigen retrieval to expose epitopes
Frozen sections: Often preserve antigen recognition but have poorer morphology
Fresh tissues: Provide optimal antigen recognition but limited structural preservation
Antigen retrieval methods:
Heat-induced epitope retrieval (HIER): Test multiple buffer systems (citrate pH 6.0, EDTA pH 8.0, Tris-EDTA pH 9.0)
Enzymatic retrieval: Consider pepsin, proteinase K, or trypsin for certain epitopes
Optimize retrieval time, temperature, and pressure conditions
Blocking conditions:
Test species-matched normal serum, BSA, casein, and commercial blockers
Include avidin-biotin blocking for biotin-based detection systems
Consider dual blocking with protein blockers and Fc receptor blockers for tissues rich in immune cells
Detection system selection:
Direct detection: Simplest but lowest sensitivity
Indirect detection: Improved sensitivity with potential for higher background
Amplification systems (ABC, TSA): Highest sensitivity but require careful optimization
Controls:
Positive tissue controls with known expression
Negative controls (no primary antibody, isotype controls)
Absorption controls with purified antigen
Development of quantitative ELISA protocols requires systematic optimization:
Antibody orientation strategy:
Direct coating: Antigen directly coated on plates
Sandwich approach: Capture antibody + antigen + detection antibody
Competitive format: Sample antigen competes with labeled antigen
Standard curve development:
Use purified recombinant protein for standard curve
Include at least 7-8 concentration points spanning expected range
Prepare standards in the same matrix as samples
Employ 4- or 5-parameter logistic curve fitting
Optimization parameters:
Coating concentration and buffer (typically carbonate buffer pH 9.6)
Blocking agent (BSA, milk proteins, commercial blockers)
Antibody concentration and incubation conditions
Wash buffer composition and number of washes
Substrate development time
Validation metrics:
Lower limit of detection (LLOD)
Lower limit of quantification (LLOQ)
Upper limit of quantification (ULOQ)
Precision: Intra-assay and inter-assay CV <15-20%
Accuracy: Recovery of spiked samples 80-120%
Linearity: Samples should dilute linearly through the assay range
Specificity: No cross-reactivity with similar proteins
Similar to neutralizing antibody tests, sample volume is critical for optimal ELISA results. Studies with other antibodies have used specific volumes (e.g., 25 μL for IgG detection) to produce optimal results .
Incorporating ENGASE2 Antibody into flow cytometry panels requires careful panel design and optimization:
Panel design considerations:
Fluorochrome selection based on antigen abundance (bright fluorochromes for low-abundance targets)
Spectral overlap minimization
Inclusion of proper controls (FMO, isotype, biological controls)
Titration optimization:
Perform antibody titration on positive and negative samples
Calculate staining index for each concentration: (MFI positive - MFI negative) / (2 × SD of negative)
Select concentration with highest staining index, not necessarily strongest signal
Buffer optimization:
Test different staining buffers (PBS/BSA/Azide, commercial buffers)
Include Fc receptor blockers for samples with immune cells
Evaluate need for specialized buffers (protein transport inhibitors, viability dyes)
Fixation considerations:
Test if antibody recognizes fixed epitopes
Optimize fixative concentration and duration
Determine compatibility with permeabilization for intracellular targets
Compensation strategy:
Use single-stained controls for each fluorochrome
Prepare compensation controls using the same cells or beads that match fluorochrome brightness
Validate compensation matrix using FMO controls
Data analysis approaches:
Define positive populations using biological controls and FMO
Consider dimensionality reduction techniques for complex panels
Implement standardized gating strategies for consistency
By systematically addressing these considerations, researchers can successfully incorporate ENGASE2 Antibody into flow cytometry panels while maintaining optimal signal-to-noise ratios for accurate data interpretation.