EFNB2 (Ab-316) Antibody

What is EFNB2 (Ab-316) Antibody and what are its basic specifications?

EFNB2 (Ab-316) Antibody is a rabbit polyclonal antibody that specifically targets the region surrounding tyrosine 316 (Y316) of human Ephrin-B2 protein. The antibody recognizes the peptide sequence around amino acids 314-318 (P-V-Y-I-V) of Ephrin-B2. It is supplied at a concentration of 1.0 mg/mL in phosphate buffered saline (without Mg²⁺ and Ca²⁺), pH 7.4, 150mM NaCl, 0.02% sodium azide, and 50% glycerol. The antibody is purified via affinity chromatography using epitope-specific immunogen and has been validated for Western blotting applications with a recommended dilution range of 1:500-1:1000.

What is the target protein (EFNB2) and what are its primary biological functions?

Ephrin-B2 (EFNB2) is a cell surface transmembrane ligand for Eph receptors, which comprise the largest subfamily of receptor protein-tyrosine kinases. EFNB2 is crucial for:

• Mediating bidirectional signaling in cell-cell interactions

• Regulating migration, repulsion, and adhesion during neuronal, vascular, and epithelial development

• Heart morphogenesis and angiogenesis through regulation of cell adhesion and migration

• Constraining the orientation of longitudinally projecting axons

• Acting as a receptor for Hendra virus and Nipah virus

EFNB2 binds to multiple receptor tyrosine kinases including EPHA4, EPHA3, and EPHB4, leading to contact-dependent bidirectional signaling. The pathway downstream of the receptor is called forward signaling, while the pathway downstream of the ephrin ligand is referred to as reverse signaling.

What species reactivity has been validated for this antibody?

The EFNB2 (Ab-316) Antibody has been validated for reactivity with human EFNB2 protein. Additionally, it reacts with mouse and rat EFNB2 due to sequence homology. The specific peptide sequence targeted by this antibody shows high conservation across these species, making it suitable for cross-species applications in mammalian research models.

What are the validated applications for EFNB2 (Ab-316) Antibody in experimental protocols?

The primary validated application for EFNB2 (Ab-316) Antibody is Western blotting (WB) with a recommended dilution of 1:500-1:1000. Some sources also indicate suitability for ELISA applications. The antibody detects endogenous levels of total Ephrin-B2 protein.

For Western blotting protocols:

• Prepare cell/tissue lysates in an appropriate lysis buffer containing protease inhibitors

• Separate proteins by SDS-PAGE (the predicted molecular weight of EFNB2 is approximately 37 kDa)

• Transfer proteins to a PVDF or nitrocellulose membrane

• Block the membrane with 5% non-fat milk or BSA in TBST

• Incubate with EFNB2 (Ab-316) Antibody at a dilution of 1:500-1:1000 overnight at 4°C

• Wash with TBST and incubate with appropriate HRP-conjugated secondary antibody

• Develop using enhanced chemiluminescence detection

How should the antibody be stored and handled to maintain optimal activity?

For optimal preservation of antibody activity:

• Short-term storage (up to 6 months): Store at 4°C

• Long-term storage: Store at -20°C

• Avoid repeated freeze-thaw cycles as they may compromise antibody performance

• After thawing for use, aliquot the antibody if frequent usage is anticipated to minimize freeze-thaw cycles

• Handle according to standard laboratory practices for antibody reagents, including using sterile technique when opening and pipetting

What controls should be included when using EFNB2 (Ab-316) Antibody?

For rigorous experimental design with this antibody, include the following controls:

• Positive control: Cell lines or tissues known to express EFNB2 (e.g., specific HCC cell lines like HCC-LM3, MHCC97-H, or SMMC 7721, which have been shown to express higher levels of EFNB2)

• Negative control: Samples from EFNB2 knockout models or cell lines with low/no expression of EFNB2 (e.g., L-02 normal liver cell line can serve as a comparative control)

• Loading control: Standard housekeeping proteins (β-actin, GAPDH, etc.) to normalize protein loading

• Peptide competition assay: Pre-incubation of the antibody with the immunizing peptide to confirm specificity

• Secondary antibody-only control: To assess non-specific binding of the secondary antibody

How can EFNB2 (Ab-316) Antibody be used to study EFNB2's role in cancer progression?

EFNB2 has been implicated in various aspects of cancer progression. Researchers can use this antibody to:

• Assess EFNB2 expression levels in different cancer cell lines and tumor tissues to correlate with clinical outcomes

• Investigate the relationship between EFNB2 phosphorylation status at Y316 and cancer cell migration, invasion, and metastasis

• Study the bidirectional signaling between EFNB2 and its receptors in the tumor microenvironment

Specifically, research has shown that EFNB2 expression is significantly higher in certain hepatocellular carcinoma (HCC) cell lines (HCC-LM3, MHCC97-H, and SMMC 7721) compared to normal liver cell lines. EFNB2 also shows higher expression in cancer tissues compared to para-carcinoma tissues (p = 0.0458). The antibody can be used to explore these differential expression patterns in various cancer types and their correlation with tumor progression.

What is the significance of studying Y316 phosphorylation of EFNB2 in signaling pathways?

The phosphorylation of EFNB2 at tyrosine 316 (Y316) is crucial for its signaling functions:

• Y316 is located in the intracellular domain of EFNB2 and is a key phosphorylation site involved in reverse signaling

• Phosphorylation at this site occurs following Eph receptor binding and plays a role in signal transduction

• The phosphorylated Y316 creates docking sites for SH2 domain-containing signaling proteins

Researchers can use this antibody to:

• Monitor changes in Y316 phosphorylation status under different cellular conditions

• Investigate how Y316 phosphorylation affects EFNB2's interaction with downstream signaling proteins

• Study the impact of various stimuli (growth factors, hypoxia, etc.) on EFNB2 phosphorylation at this site

• Examine the relationship between phosphorylation status and cellular responses like migration or adhesion

How can EFNB2 (Ab-316) Antibody be used to investigate the role of EFNB2 in viral infections?

EFNB2 serves as a receptor for Hendra virus and Nipah virus, making it relevant for viral infection research. The antibody can be utilized to:

• Assess EFNB2 expression levels in target cells susceptible to viral infection

• Investigate whether Y316 phosphorylation affects viral binding or entry

• Study changes in EFNB2 expression or phosphorylation status during viral infection

• Develop blocking strategies by targeting the EFNB2 protein to prevent viral entry

Research has shown that EFNB2 surface expression can be measured via antibody staining, and the binding of viral G glycoprotein to EFNB2 can be assessed. When EFNB2 interaction was blocked by co-incubation with a representative Fc-fused Eph receptor (EphB2-Fc), it inhibited infection of EFNB2-expressing cells by competing with NiV-G pseudotyped viruses.

What factors might affect the specificity and sensitivity of EFNB2 (Ab-316) Antibody in Western blotting?

Several factors can influence antibody performance:

• Sample preparation:

  • Complete lysis of cells/tissues is essential for accessing the EFNB2 protein

  • Use of appropriate protease and phosphatase inhibitors to prevent protein degradation and preserve phosphorylation status

  • Proper denaturation of the sample to expose the epitope

• Blocking conditions:

  • Optimization of blocking buffer (BSA vs. non-fat milk) may be necessary

  • Insufficient blocking can lead to non-specific binding and background

• Antibody concentration:

  • Using the recommended dilution range (1:500-1:1000)

  • Titration may be necessary for optimal signal-to-noise ratio

• Incubation conditions:

  • Optimal incubation temperature and time

  • Sufficient washing steps to remove unbound antibody

• Detection method:

  • Selection of appropriate secondary antibody

  • Optimization of exposure time for chemiluminescence detection

How can researchers validate that the antibody is specifically detecting EFNB2 in their experimental system?

Validation strategies include:

• Peptide competition assay:

  • Pre-incubate the antibody with the immunizing peptide

  • Loss of signal indicates specificity for the target epitope

• Genetic validation:

  • Use of EFNB2 knockout or knockdown models

  • Reduction or loss of signal confirms specificity

• Comparison with other validated anti-EFNB2 antibodies:

  • Detection of the same band/pattern with antibodies targeting different epitopes

• Mass spectrometry confirmation:

  • Immunoprecipitation followed by mass spectrometry analysis

  • Confirms the identity of the detected protein

• Recombinant protein controls:

  • Use purified recombinant EFNB2 as a positive control

  • Confirms antibody recognition of the protein of interest

How can researchers optimize immunoprecipitation protocols using this antibody?

While not explicitly validated for immunoprecipitation, researchers interested in using this antibody for IP can consider:

• Starting conditions:

  • Use 1-5 μg of antibody per 200-500 μg of total protein

  • Prepare lysates in non-denaturing buffers to preserve protein conformation

• Pre-clearing the lysate:

  • Incubate lysate with beads alone to reduce non-specific binding

• Antibody-bead coupling:

  • Pre-couple the antibody to protein A/G beads before adding lysate

  • Alternatively, incubate antibody with lysate first, then add beads

• Incubation conditions:

  • Overnight incubation at 4°C with gentle rotation

  • Avoid harsh washing conditions that might disrupt antibody-antigen binding

• Elution and detection:

  • Use mild elution conditions to preserve antibody for reuse

  • Confirm successful IP by Western blotting with another anti-EFNB2 antibody targeting a different epitope

How can EFNB2 (Ab-316) Antibody be used to study EFNB2's role in immune cell function and migration?

EFNB2 plays significant roles in immune cell function that can be investigated using this antibody:

• T cell chemotaxis and migration in multiple sclerosis (MS):

  • EFNB1 and EFNB2 regulate T cell chemotaxis and migration in experimental autoimmune encephalomyelitis (EAE) and MS

  • T cells with double deletion of EFNB1 and EFNB2 show reduced proliferation in response to MOG35-55 and defective Th1 and Th17 differentiation

  • These T cells are compromised in their ability to migrate into the CNS in vivo and towards multiple chemokines in vitro

• Methodological approach:

  • Use the antibody to assess EFNB2 expression in different T cell subsets (Th1, Th17)

  • Correlate EFNB2 expression/phosphorylation with migratory capacity

  • Perform immunohistochemistry to detect EFNB2-expressing T cells in MS lesions

  • Study changes in EFNB2 phosphorylation status during T cell activation and migration

What are the considerations for using this antibody to investigate EFNB2's role in angiogenesis and tumor vascularization?

EFNB2 plays critical roles in angiogenesis that can be studied using this antibody:

• Tumor angiogenesis:

  • EFNB2 expression in tumor cells and endothelial cells affects tumor vascularization

  • EFNB2 reverse signaling enables VEGF receptor endocytosis, essential for angiogenesis

  • High EFNB2 expression drives perivascular invasion of glioblastoma cancer stem cells

• Research approaches:

  • Use the antibody to assess EFNB2 expression in tumor vasculature versus normal vasculature

  • Correlate EFNB2 expression/phosphorylation status with tumor vessel density and morphology

  • Investigate the relationship between EFNB2 expression and hypoxia-induced angiogenesis

  • Study the interplay between EFNB2 and other angiogenic factors like VEGF

• Experimental models:

  • Co-culture systems of tumor cells and endothelial cells

  • In vivo tumor angiogenesis models

  • 3D spheroid models to assess vascular sprouting

How can researchers use this antibody to investigate the relationship between EFNB2 and cancer immunotherapy responses?

Recent research indicates EFNB2's role in the tumor immune microenvironment, which can be explored using this antibody:

• EFNB2 in immune evasion:

  • EFNB2 expressed in cancer cells and vascular cells can support immune evasion

  • It increases immunosuppressive myeloid cells and decreases CD8+ T-cell activation in tumors

  • Inhibition of EFNB2-EphB receptor bidirectional signaling with EFNB2 antibodies can sensitize tumors to radiation therapy

• Research strategies:

  • Assess EFNB2 expression in tumor samples from patients with different responses to immunotherapy

  • Correlate EFNB2 phosphorylation status with immune cell infiltration patterns

  • Investigate how modulating EFNB2 expression/activity affects response to immune checkpoint inhibitors

• Experimental design:

  • Multiparameter flow cytometry to simultaneously analyze EFNB2 expression and immune cell populations

  • Spatial transcriptomics combined with immunohistochemistry to map EFNB2 expression relative to immune cell localization in tumor samples

  • In vivo models comparing immunotherapy efficacy in EFNB2-high versus EFNB2-low tumors

How should researchers interpret variations in EFNB2 expression patterns across different cancer types?

The interpretation of EFNB2 expression data requires consideration of several factors:

When analyzing expression data:

• Consider cell type-specific expression (tumor cells vs. stromal/vascular cells)

• Assess correlation with clinical parameters (stage, grade, survival)

• Examine relationship with known molecular subtypes of the cancer

• Evaluate expression in context of the tumor microenvironment

What are the challenges in correlating EFNB2 phosphorylation status with functional outcomes in research?

Several challenges exist when attempting to correlate EFNB2 phosphorylation with functional outcomes:

• Technical challenges:

  • Phosphorylation events are often transient and can be lost during sample preparation

  • Multiple phosphorylation sites may be present, requiring site-specific antibodies

  • Quantification of phosphorylation levels requires careful normalization

• Biological complexity:

  • Y316 phosphorylation may have different functional consequences depending on cell type and context

  • Both forward and reverse signaling occur simultaneously in physiological settings

  • Cross-talk with other signaling pathways may influence outcomes

• Interpretation considerations:

  • Correlation doesn't necessarily indicate causation

  • Need for functional validation through mutation studies (Y316F phospho-null mutants)

  • Requirement for temporal analysis of phosphorylation events

• Experimental approaches to address these challenges:

  • Use of phosphatase inhibitors during sample preparation

  • Complementary approaches like mass spectrometry for phosphorylation site mapping

  • Genetic manipulation to create phospho-mimetic or phospho-null mutants

What statistical approaches are most appropriate for analyzing EFNB2 expression data in correlation with clinical outcomes?

When analyzing EFNB2 expression data in relation to clinical outcomes, consider these statistical approaches:

• Survival analysis:

  • Kaplan-Meier curves with log-rank tests to compare survival between EFNB2-high and EFNB2-low groups

  • Cox proportional hazards regression for multivariate analysis, adjusting for confounding variables

• Correlation analysis:

  • Spearman's rank correlation for non-parametric assessment of relationship between EFNB2 expression and continuous variables

  • Example: EFNB2 expression showed positive correlation with various immune cell populations (e.g., dendritic cells: Rho = 0.427, p = 9.29e-17)

• Group comparisons:

  • t-tests or Mann-Whitney U tests for comparing EFNB2 expression between two groups

  • ANOVA or Kruskal-Wallis for comparisons across multiple groups

  • Example: EFNB2 expression was significantly higher in cancer tissues than in para-carcinoma tissues (p = 0.0458)

• Predictive modeling:

  • Machine learning approaches to identify if EFNB2 expression/phosphorylation status contributes to predictive models of treatment response

  • Regularized regression methods (LASSO, ridge) for high-dimensional data

• Multiple testing correction:

  • Apply appropriate corrections (Bonferroni, FDR) when performing multiple comparisons

  • Example: When correlating EFNB2 with multiple immune cell types, p-values should be adjusted accordingly

How might EFNB2 (Ab-316) Antibody be used in single-cell analyses to understand heterogeneity in EFNB2 signaling?

Single-cell approaches offer new opportunities for investigating EFNB2 biology:

• Single-cell western blotting:

  • Detect EFNB2 expression and Y316 phosphorylation at the single-cell level

  • Reveal heterogeneity in EFNB2 signaling within tumor or tissue samples

  • Correlate with other signaling molecules at single-cell resolution

• Mass cytometry (CyTOF):

  • Simultaneous detection of EFNB2, phosphorylation status, and multiple cellular markers

  • Identify rare cell populations with distinct EFNB2 signaling profiles

  • Example protocol: conjugate EFNB2 (Ab-316) Antibody to a metal isotope for use in CyTOF panels

• Imaging mass cytometry:

  • Spatial mapping of EFNB2 expression and phosphorylation in tissue sections

  • Preserve tissue architecture while obtaining single-cell resolution data

  • Analyze EFNB2 in relation to the local microenvironment

• Integration with single-cell RNA-seq:

  • Correlate protein-level EFNB2 data with transcriptomic profiles

  • CITE-seq approaches combining antibody detection with RNA sequencing

  • Reconstruct EFNB2 signaling networks at single-cell resolution

What are the potential applications of EFNB2 (Ab-316) Antibody in therapeutic development research?

This antibody could support therapeutic development in several ways:

• Target validation:

  • Confirm EFNB2 expression and phosphorylation status in disease models

  • Correlate Y316 phosphorylation with disease progression or treatment response

  • Validate genetic knockdown results at the protein level

• Mechanism of action studies:

  • Investigate how candidate therapeutics affect EFNB2 expression or phosphorylation

  • Monitor changes in downstream signaling pathways

  • Example: EphB2-Fc has been shown to compete with NiV-G pseudotyped viruses for EFNB2 binding sites

• Patient stratification biomarker development:

  • Assess if EFNB2 expression/phosphorylation status predicts response to specific therapies

  • Develop immunohistochemistry protocols for potential clinical use

  • Example: In pancreatic cancer models, EFNB2 antibody treatment sensitized tumors to radiation therapy

• Therapeutic antibody development:

  • Use as a reference antibody when developing therapeutic antibodies targeting EFNB2

  • Compare binding profiles and functional effects

  • Screen for antibodies that specifically modulate Y316 phosphorylation

How can researchers design multiplex immunoassays incorporating EFNB2 (Ab-316) Antibody to study signaling networks?

Multiplex approaches enable comprehensive analysis of signaling networks:

• Multiplexed western blotting:

  • Sequential or simultaneous detection of EFNB2, phospho-EFNB2, Eph receptors, and downstream signaling proteins

  • Use of different fluorophore-conjugated secondary antibodies

  • Appropriate antibody stripping and reincubation protocols

• Reverse phase protein arrays (RPPA):

  • High-throughput analysis of EFNB2 expression across multiple samples

  • Inclusion in phospho-protein panels to assess activation of related pathways

  • Correlation with treatment responses or disease progression

• Proximity ligation assays:

  • Detect protein-protein interactions involving EFNB2

  • Combine EFNB2 (Ab-316) Antibody with antibodies against known or putative interaction partners

  • Visualize and quantify interactions in situ with subcellular resolution

• Bead-based multiplex assays:

  • Development of custom panels including EFNB2 phosphorylation

  • Simultaneous measurement of multiple cytokines and signaling molecules

  • Application to cell culture supernatants or tissue lysates

• Design considerations:

  • Antibody compatibility (species, isotype)

  • Cross-reactivity testing

  • Optimization of detection methods for balanced sensitivity