fur4 Antibody

What is Furin and what role does it play in cellular processes?

Furin is a cellular endoprotease that belongs to the proprotein convertase subtilisin/kexin (PCSK) family, also known as PCSK3. It functions as a dibasic-processing enzyme that cleaves precursor proteins at paired basic amino acid residue sites . This enzyme plays crucial roles in various cellular processes including protein processing, activation of growth factors, and viral protein processing. Furin is expressed in multiple tissue types and localizes primarily to the trans-Golgi network, though it can cycle between different cellular compartments including the cell surface and endosomes.

What applications are Furin antibodies commonly used for in research?

Furin antibodies are extensively used in multiple research applications, primarily:

• Western blotting (WB) for protein detection and quantification

• Immunocytochemistry (ICC) for localization studies

• Immunofluorescence (IF) for visualization of cellular distribution

These antibodies are valuable tools for studying Furin's role in normal cellular functions as well as in pathological conditions such as viral infections, cancer progression, and other diseases where protein processing is dysregulated .

How do I select the appropriate Furin antibody for my research?

When selecting a Furin antibody, consider the following factors:

• Target species compatibility: Ensure the antibody recognizes your species of interest. For example, some Furin antibodies like ab3467 are tested and validated for human and mouse samples .

• Application suitability: Verify the antibody is validated for your specific application (WB, ICC, etc.).

• Epitope recognition: Check which region of Furin the antibody targets. For example, ab3467 recognizes a synthetic peptide within human FURIN at the C-terminus .

• Validation data: Review available data from publications and manufacturer testing to confirm specificity and performance.

• Clonality: Determine whether a polyclonal antibody (broader epitope recognition) or monoclonal antibody (single epitope specificity) is more suitable for your research needs.

What are the optimal conditions for using Furin antibody in Western blot applications?

For optimal Western blot results with Furin antibody:

• Sample preparation: Use appropriate lysis buffers that preserve protein integrity while efficiently extracting Furin.

• Protein loading: Load 20-25 μg of total protein per lane as demonstrated in successful experiments with FURIN antibodies .

• Gel selection: Use 4-20% tris-glycine gels under reducing conditions for optimal separation of Furin (predicted band size: 87 kDa) .

• Antibody dilution: For ab3467, a 1/1000 dilution has been successfully used in Western blot applications .

• Secondary antibody: Use HRP-conjugated or fluorescently-labeled species-appropriate secondary antibodies at manufacturer-recommended dilutions.

• Controls: Include positive controls (cells known to express Furin) and negative controls (FURIN knockout cells or lines with very low expression) .

• Exposure time: Start with 1-minute exposure and adjust based on signal intensity .

How should I optimize immunofluorescence protocols when using Furin antibodies?

For immunofluorescence using Furin antibodies:

• Fixation: Methanol fixation has been successfully used for Furin antibody applications .

• Blocking: Use 2% BSA to minimize non-specific binding .

• Primary antibody concentration: For ab3467, a concentration of 2 μg/ml has yielded good results .

• Incubation conditions: Optimize time and temperature based on your specific experimental system.

• Secondary antibody selection: For fluorescence visualization, Alexa Fluor® 488-conjugated secondary antibodies at approximately 1/2000 dilution have proven effective .

• Nuclear counterstaining: DAPI can be used for nuclear visualization in conjunction with Furin staining .

• Cytoskeletal co-staining: Consider co-staining with cytoskeletal markers (e.g., α-tubulin) using differentially labeled secondary antibodies for subcellular localization studies .

What methods can be used to conjugate Furin antibodies to nanoparticles for advanced applications?

Furin antibodies can be conjugated to nanoparticles using several approaches, with click chemistry being particularly effective:

• DBCO-azide click chemistry method:

  • Functionalize the antibody with DBCO-PEG4-NHS ester in borate buffer (pH 8.5)

  • Prepare azide-functionalized nanoparticles

  • React the DBCO-labeled antibody with azide-functionalized nanoparticles in a copper-free click reaction

• Fluorescent labeling for tracking:

  • Dual labeling can be achieved by simultaneously adding fluorescent NHS ester (e.g., Atto488-NHS) during the DBCO functionalization step

  • This enables visualization of antibody-nanoparticle conjugates in cellular systems

• Purification of conjugates:

  • Purify labeled antibodies using 40K Zeba desalting columns to remove unreacted components

  • Purify antibody-nanoparticle conjugates by low-speed centrifugation (700 RPM) followed by redispersion in appropriate buffer

How should I address unexpected results or data that contradicts my hypothesis when using Furin antibodies?

When faced with contradictory results in Furin antibody experiments:

• Examine data thoroughly: Carefully analyze all data points, paying special attention to outliers that may influence results .

• Validate antibody specificity: Confirm antibody specificity using appropriate controls, including:

  • FURIN knockout cell lines as negative controls

  • Multiple cell types with varying Furin expression levels

  • Alternative antibody clones targeting different epitopes

• Consider technical variables:

  • Sample preparation methods might affect epitope accessibility

  • Fixation protocols could impact antibody binding

  • Buffer composition may influence antibody performance

• Evaluate alternative explanations: Consider whether the contradictory data might reveal new insights about Furin biology rather than representing experimental error .

• Refine experimental variables: Modify protocols to include additional controls or refine existing variables to better understand the unexpected results .

What are common challenges in detecting Furin in different cell lines and how can they be addressed?

Detection of Furin across different cell lines presents several challenges:

• Variable expression levels: Furin expression varies significantly across cell types. Western blot analysis showed strong detection in HEK-293 and MOLT-4 cells, while expression patterns differ in HAP1 and Ramos cells .

• Subcellular localization differences: Furin can shuttle between different cellular compartments, potentially affecting detection efficiency.

• Solutions to common challenges:

  • Perform pilot studies to determine optimal protein loading for each cell line

  • Use CRISPR Furin knockout cells as negative controls to confirm specificity

  • Consider cell-specific optimization of lysis and extraction protocols

  • Adjust antibody concentrations based on expression levels in target cells

How can I validate the specificity of my Furin antibody results?

To validate Furin antibody specificity:

• Use genetic knockout controls: CRISPR-generated Furin knockout cell lines provide definitive negative controls, as demonstrated with HAP1 FURIN CRISPR KO clones .

• Employ multiple detection methods: Confirm findings using orthogonal techniques (WB, ICC, IF) to strengthen confidence in results.

• Peptide competition assay: Pre-incubate the antibody with the immunizing peptide to block specific binding sites before application to samples.

• Cross-reference with alternative antibodies: Use antibodies targeting different epitopes of Furin to confirm consistent detection patterns.

• RNA-level validation: Correlate protein detection with mRNA expression using RT-PCR or RNA-seq data.

How can epitope-specific antibodies be developed and characterized for targeting specific functional domains of Furin?

Development of epitope-specific Furin antibodies requires:

• Epitope selection strategy:

  • Identify functionally important domains in Furin structure

  • Select conserved regions for broader reactivity or variable regions for specificity

  • Consider accessibility of the epitope in native protein conformation

• Immunization and hybridoma development:

  • Immunize animals with synthetic peptides corresponding to target epitopes

  • Generate hybridoma cells by fusing splenocytes with myeloma cells

  • Screen hybridoma supernatants using ELISA and cytofluorometric analyses for binding specificity

• Epitope mapping:

  • Use peptide arrays or mutational analysis to precisely define the recognized epitope

  • Compare binding properties with natural ligands (similar to studies with MAX.16H5 antibody)

  • Evaluate epitope conservation across species if cross-reactivity is desired

• Functional characterization:

  • Assess whether the antibody interferes with enzyme activity

  • Determine if epitope recognition is affected by post-translational modifications

  • Investigate antibody-mediated effects on Furin trafficking and localization

What strategies can improve antibody affinity and specificity through structure-guided design?

Structure-guided antibody engineering can enhance Furin antibody performance:

• Computational analysis of antibody-antigen interface:

  • Analyze interatomic interactions between antibody and Furin epitope

  • Apply network theory to compute inter-residue atomic interactions

  • Identify key residues for binding affinity and specificity

• Strategic mutations:

  • Introduce affinity-enhancing point mutations in complementarity-determining regions (CDRs)

  • Consider strategic deletions that can improve binding characteristics (as demonstrated with Ab513)

• Humanization strategy:

  • Retain CDRs from the original antibody while replacing framework regions with human sequences

  • Carefully monitor potential effects on binding affinity during humanization

• Affinity maturation:

  • Generate libraries with variations in key binding residues

  • Screen for variants with improved affinity while maintaining specificity

• Validation of improved variants:

  • Quantify affinity improvements through surface plasmon resonance or bio-layer interferometry

  • Confirm that specificity is maintained or enhanced after engineering

How can Furin antibodies be utilized for studying Furin's role in viral infection mechanisms?

Furin antibodies offer valuable tools for investigating Furin's role in viral infections:

• Visualization of Furin-virus interactions:

  • Use immunofluorescence microscopy to track co-localization of Furin with viral proteins

  • Employ dual-labeled antibodies to monitor temporal dynamics during infection

• Inhibition studies:

  • Apply Furin antibodies that block the active site to assess functional consequences

  • Compare viral processing efficiency in the presence of blocking vs. non-blocking antibodies

• Trafficking analysis:

  • Track changes in Furin subcellular distribution during viral infection

  • Correlate Furin redistribution with stages of viral replication

• Quantification of Furin upregulation:

  • Measure changes in Furin expression levels during infection using quantitative Western blotting

  • Compare Furin expression across different viral strains and cell types

• Nanoparticle-conjugated antibody applications:

  • Deliver Furin-targeting interventions using antibody-conjugated nanoparticles

  • Track cellular uptake and distribution using fluorescently labeled antibody-nanoparticle conjugates

What emerging technologies are expanding the applications of Furin antibodies in research?

Emerging technologies are creating new opportunities for Furin antibody applications:

• Single-cell antibody profiling: Analyzing Furin expression and activity at the single-cell level to understand cellular heterogeneity.

• Super-resolution microscopy: Enabling nanoscale visualization of Furin distribution and dynamics within cellular compartments.

• Bi-specific antibody development: Creating antibodies that simultaneously target Furin and interacting partners to study complex formation.

• Intrabody approaches: Developing antibody fragments that can function within living cells to track or modulate Furin activity in real-time.

• Antibody-drug conjugates: Utilizing Furin antibodies to deliver therapeutic payloads specifically to cells with altered Furin expression or activity.

How can researchers integrate Furin antibody data with other omics approaches for comprehensive insights?

Integration of Furin antibody data with other omics approaches offers more comprehensive understanding:

• Proteomics integration:

  • Correlate Furin expression levels determined by antibody-based methods with global proteomic profiles

  • Identify potential Furin substrates by comparing proteomes before and after Furin inhibition

• Transcriptomics correlation:

  • Compare antibody-detected protein levels with mRNA expression data

  • Identify discrepancies that might indicate post-transcriptional regulation

• Structural biology interfaces:

  • Use antibody epitope mapping data to inform structural studies of Furin

  • Develop antibodies that recognize specific conformational states of Furin

• Systems biology approaches:

  • Incorporate antibody-derived quantitative data into mathematical models of cellular pathways

  • Predict system-wide effects of Furin modulation based on integrated datasets

• Clinical sample analysis:

  • Apply validated antibodies to patient samples for correlative studies

  • Connect basic research findings to clinical observations through consistent antibody-based detection methods