fnx2 Antibody

What epitope specificity should I consider when selecting a FNIP2 antibody?

When selecting a FNIP2 antibody, epitope specificity is crucial for experimental success. Available antibodies target different regions of the FNIP2 protein, including N-terminal and C-terminal domains. For instance, the polyclonal antibody ABIN2268382 targets amino acids 783-812 in the C-terminal region of human FNIP2 . The epitope location can significantly impact antibody functionality in different applications:

• C-terminal antibodies (e.g., those targeting AA 783-812) may be preferable when studying protein-protein interactions where the C-terminus is exposed

• N-terminal antibodies (e.g., those targeting AA 100-150) might be more suitable when the C-terminus is potentially occluded in protein complexes

Always confirm that your selected antibody's epitope is accessible in your experimental context, especially when working with fusion proteins or fixed tissues.

What is the difference between FNIP1 and FNIP2 antibodies, and how can I ensure specificity?

FNIP1 and FNIP2 share approximately 49% sequence homology, creating potential cross-reactivity challenges. To ensure specificity:

• Select antibodies raised against unique regions with minimal sequence similarity

• Perform validation experiments using:

  • Western blots comparing FNIP1 and FNIP2 recombinant proteins

  • Immunoprecipitation followed by mass spectrometry

  • siRNA knockdown of FNIP1 and FNIP2 separately to confirm signal reduction is specific

  • Peptide competition assays with specific blocking peptides

The FNIP2 antibody ABIN2268382 was generated using a KLH-conjugated synthetic peptide spanning amino acids 783-812 from the C-terminal region of human FNIP2, which helps ensure specificity against this target .

What are the validated applications for FNIP2 antibodies in research?

FNIP2 antibodies have been validated for multiple research applications, each with specific considerations:

The FNIP2 antibody ABIN2268382 has been specifically validated for Western Blotting, ELISA, Immunohistochemistry, and Flow Cytometry applications with human samples . When applying these antibodies to non-validated applications, titration experiments and appropriate controls are essential.

How should I design experiments to study FNIP2 interactions with Folliculin (FLCN)?

When studying FNIP2-FLCN interactions, consider the following experimental design:

• Co-immunoprecipitation (Co-IP):

  • Use FNIP2 antibodies targeting regions not involved in FLCN binding

  • Include controls with IgG from the same species as the FNIP2 antibody

  • Consider reciprocal IP with FLCN antibodies to confirm interactions

• Proximity Ligation Assay (PLA):

  • Combine FNIP2 antibody (e.g., ABIN2268382) with validated FLCN antibodies

  • Include negative controls omitting one primary antibody

  • Use cellular models with known FNIP2/FLCN expression patterns

• Microscopy approaches:

  • Use differentially tagged fluorescent antibodies for FNIP2 and FLCN

  • Confirm specificity with peptide competition assays

  • Consider super-resolution techniques for detailed co-localization studies

Always validate FNIP2 antibody specificity before complex interaction studies, as non-specific binding can lead to false-positive results.

What sample preparation protocols optimize FNIP2 detection in Western blotting?

Optimizing sample preparation for FNIP2 detection requires careful consideration of protein extraction and handling:

• Lysis buffer composition:

  • Use RIPA buffer supplemented with 1% NP-40, 0.5% sodium deoxycholate, and 0.1% SDS

  • Include protease inhibitors (PMSF, aprotinin, leupeptin) and phosphatase inhibitors

  • Add 1mM DTT to preserve epitope accessibility for C-terminal targeting antibodies like ABIN2268382

• Sample processing:

  • Maintain samples at 4°C during processing

  • Sonicate briefly (3-5 pulses) to shear DNA and reduce viscosity

  • Centrifuge at 14,000g for 15 minutes to remove insoluble debris

• Protein denaturation:

  • Heat samples at 95°C for 5 minutes in Laemmli buffer containing 5% β-mercaptoethanol

  • For membrane-associated FNIP2 complexes, consider gentler denaturation (70°C for 10 minutes)

• Gel electrophoresis:

  • Use 7.5-10% polyacrylamide gels to properly resolve the 122 kDa FNIP2 protein

  • Include gradient gels (4-15%) for studying FNIP2 complexes

These protocols maximize epitope accessibility for antibodies targeting the C-terminal region, such as ABIN2268382, which recognizes amino acids 783-812 .

How can I optimize immunohistochemistry protocols for FNIP2 detection in different tissue types?

Optimizing IHC protocols for FNIP2 detection requires tissue-specific adaptations:

• Fixation considerations:

  • For formalin-fixed paraffin-embedded (FFPE) tissues: Limit fixation to 24 hours

  • For frozen sections: Fix with 4% paraformaldehyde for 15 minutes post-sectioning

• Antigen retrieval methods:

  • Heat-induced epitope retrieval: Citrate buffer (pH 6.0) at 95°C for 20 minutes

  • For C-terminal antibodies like ABIN2268382: Tris-EDTA buffer (pH 9.0) may preserve epitope accessibility

• Blocking and antibody incubation:

  • Block with 5% normal serum (from secondary antibody host species)

  • Add 0.1% Triton X-100 for improved antibody penetration

  • Incubate with primary antibody (1:100 dilution) overnight at 4°C

• Detection systems:

  • For tissues with low FNIP2 expression: Use signal amplification (TSA)

  • For dual staining: Select enzymatic substrates with spectral separation

• Controls and validation:

  • Include tissue with known FNIP2 expression as positive control

  • Use peptide competition (with immunizing peptide AA 783-812) to verify specificity

These optimized protocols help maintain the integrity of the C-terminal epitopes recognized by antibodies such as ABIN2268382 .

How should I interpret variable FNIP2 banding patterns in Western blots?

FNIP2 antibodies may show multiple bands on Western blots, requiring careful interpretation:

• Expected molecular weights:

  • Full-length FNIP2: ~122 kDa

  • Known splice variants: 90-100 kDa

  • Post-translationally modified forms: 130-150 kDa

• Potential causes of multiple bands:

  • Phosphorylation: FNIP2 contains multiple phosphorylation sites

  • Proteolytic processing: C-terminal fragments (40-60 kDa) when using C-terminal antibodies like ABIN2268382

  • Cross-reactivity: Potential detection of FNIP1 (~130 kDa) due to homology

• Validation approaches:

  • Dephosphorylation assays: Treat lysates with lambda phosphatase

  • Peptide competition: Pre-incubate antibody with immunizing peptide (AA 783-812)

  • siRNA knockdown: Confirm which bands decrease with FNIP2-specific siRNA

• Tissue-specific considerations:

  • Expression patterns vary across tissues

  • Developmental stage affects processing and modification

When using C-terminal antibodies like ABIN2268382, confirm that observed bands correspond to the expected molecular weight range for FNIP2 or its known processed forms .

What controls are essential for validating FNIP2 antibody specificity in research applications?

Rigorous validation of FNIP2 antibody specificity requires multiple complementary controls:

• Positive controls:

  • Cell lines with verified FNIP2 expression (e.g., HEK293, HeLa)

  • Recombinant FNIP2 protein (full-length or fragment containing the targeted epitope)

  • Tissues with documented FNIP2 expression (kidney, liver)

• Negative controls:

  • FNIP2 knockout cell lines (CRISPR/Cas9-generated)

  • FNIP2 siRNA-treated samples

  • Primary antibody omission controls

• Specificity controls:

  • Peptide competition with immunizing peptide (AA 783-812 for ABIN2268382)

  • Testing against recombinant FNIP1 to assess cross-reactivity

  • Secondary antibody-only controls

• Application-specific controls:

  • For IHC: Isotype control antibodies at matching concentrations

  • For IP: IgG from same species and at same concentration

  • For flow cytometry: FMO (fluorescence minus one) controls

Documenting these controls is essential for research publication and ensures that observed signals genuinely represent FNIP2 rather than non-specific binding.

How can I apply FNIP2 antibodies to study its role in AMPK signaling and metabolic regulation?

Investigating FNIP2's role in AMPK signaling requires sophisticated experimental approaches:

• Co-localization studies:

  • Use FNIP2 antibodies (e.g., ABIN2268382) alongside AMPK antibodies

  • Apply super-resolution microscopy to visualize protein complexes

  • Quantify co-localization coefficients under different metabolic states

• Interaction analysis:

  • Proximity ligation assays to detect FNIP2-AMPK interactions in situ

  • Co-immunoprecipitation under different energetic states (glucose deprivation, AICAR treatment)

  • FRET microscopy using labeled antibodies to measure dynamic interactions

• Phosphorylation analysis:

  • Combine FNIP2 antibodies with phospho-specific antibodies

  • Use phosphatase treatments to determine phosphorylation-dependent interactions

  • Apply quantitative mass spectrometry following FNIP2 immunoprecipitation

• Metabolic manipulation experiments:

  • Monitor FNIP2-AMPK complex formation during:

    • Glucose starvation

    • Hypoxia

    • mTOR inhibition

  • Correlate complex formation with metabolic readouts (ATP levels, AMPK substrate phosphorylation)

These approaches leverage the specificity of antibodies like ABIN2268382 to elucidate FNIP2's dynamic role in metabolic signaling networks .

What are the methodological considerations for studying FNIP2 in relation to tumor suppression?

Investigating FNIP2's potential tumor suppressive functions requires specialized methodological approaches:

• Expression analysis in tumor tissues:

  • Use FNIP2 antibodies for tissue microarray analysis

  • Quantify expression levels using digital pathology tools

  • Correlate with clinical parameters and survival data

• Functional assays with antibody-based detection:

  • Cell proliferation: Monitor FNIP2 expression changes during cell cycle (flow cytometry)

  • Apoptosis: Dual staining for FNIP2 and apoptotic markers

  • Migration: Immunofluorescence monitoring of FNIP2 localization during cell movement

• Pathway analysis:

  • Investigate FNIP2-Folliculin-mTOR axis using co-immunoprecipitation

  • Monitor FNIP2 levels after treatment with pathway inhibitors

  • Use proximity ligation assays to detect context-dependent interactions

• In vivo models:

  • Immunohistochemistry of xenograft tumors with manipulated FNIP2 levels

  • Correlate FNIP2 expression with tumor progression markers

  • Apply multiplexed antibody panels for comprehensive pathway analysis

What emerging technologies can enhance FNIP2 antibody applications in research?

Emerging technologies are expanding the capabilities of FNIP2 antibody applications:

• Single-cell protein analysis:

  • Mass cytometry (CyTOF) with FNIP2 antibodies for multiparameter analysis

  • Single-cell Western blotting for heterogeneity studies

  • Imaging mass cytometry for spatial FNIP2 expression in tissues

• Proximity-based technologies:

  • BioID or TurboID labeling combined with FNIP2 immunoprecipitation

  • APEX2 proximity labeling to map FNIP2 interactome

  • Intrabody development based on C-terminal binding antibodies like ABIN2268382

• Antibody engineering approaches:

  • Development of recombinant nanobodies against FNIP2

  • Bispecific antibodies to study FNIP2 in protein complexes

  • Optogenetic-antibody fusions for controlled binding studies

• High-throughput screening applications:

  • Automated immunofluorescence for FNIP2 localization

  • Microfluidic antibody arrays for protein interaction studies

  • RPPA (reverse phase protein array) for quantitative pathway analysis

These emerging technologies will continue to enhance our ability to study FNIP2 biology with increasing precision and contextual information.