PEX11B Antibody

What is PEX11B and what is its biological function?

PEX11B is a peroxisomal membrane protein that functions as a key regulator of peroxisome proliferation in mammalian cells. It is involved in peroxisomal proliferation as demonstrated in multiple studies . The protein promotes membrane protrusion and elongation on the peroxisomal surface, which is a critical early step in the peroxisome division process . PEX11B may also regulate peroxisome division by recruiting the dynamin-related GTPase DNM1L to the peroxisomal membrane, facilitating the scission events necessary for peroxisome biogenesis . The human PEX11B gene (Gene ID 8799) encodes a protein with a calculated molecular weight of approximately 28 kDa . PEX11B has several alternative names including peroxisomal membrane protein 11B, peroxin-11B, peroxisomal biogenesis factor 11B, and protein PEX11 homolog beta (PEX11-beta) .

What types of PEX11B antibodies are available and what are their characteristics?

Multiple types of PEX11B antibodies are available for research applications, with polyclonal rabbit antibodies being the most common format. Commercial sources offer polyclonal antibodies that recognize epitopes within different regions of the PEX11B protein, such as amino acids 100-200 of human PEX11B or amino acids 132-177 of human Peroxin-11B . These antibodies are typically purified using antigen affinity chromatography methods to ensure high specificity . Most commercial PEX11B antibodies are supplied in liquid form, often in PBS buffer containing sodium azide and glycerol for stability during storage . The antibodies are generally unconjugated, allowing researchers flexibility in detection methods when designing experiments . Most available antibodies show cross-reactivity with human, mouse, and rat PEX11B, making them versatile tools for comparative studies across mammalian model systems .

What are the validated applications for PEX11B antibodies?

PEX11B antibodies have been validated for multiple experimental applications, providing researchers with versatile tools for studying this protein. Western blot analysis is a primary application, with validated antibodies typically used at dilutions ranging from 1:500 to 1:1000, detecting the predicted band size of 28 kDa in various cell lysates including MCF-7, Raw264.7, and PC12 cells . Immunohistochemistry on paraffin-embedded tissues (IHC-P) is another verified application, with optimal dilutions around 1:200, as demonstrated in human breast tissue analysis . Immunocytochemistry (ICC) has also been validated for cellular localization studies of PEX11B, providing insights into its distribution within peroxisomal membranes . Additionally, immunoprecipitation (IP) applications have been validated for studying PEX11B protein interactions and post-translational modifications . Some antibodies have also been validated for ELISA applications, offering quantitative analysis options for PEX11B expression levels .

What controls should be included when using PEX11B antibodies?

Including appropriate controls is essential for ensuring the validity and reliability of experiments utilizing PEX11B antibodies. Positive controls should include samples known to express PEX11B, such as MCF-7, Raw264.7, or PC12 cell lysates, which have been validated in Western blot applications . A negative control using PEX11B knockdown samples, such as those generated through shRNA expression targeting PEX11B, can help confirm antibody specificity as demonstrated in studies using doxycycline-inducible shRNA systems . Loading controls for Western blot should include housekeeping proteins like GAPDH, which was used at a dilution of 1:5000 in published PEX11B studies . When performing immunohistochemistry or immunocytochemistry, a secondary antibody-only control should be included to assess background staining levels. For competitive inhibition controls, pre-incubation of the antibody with the immunizing peptide (such as the synthetic peptide corresponding to amino acids 132-177 of human Peroxin-11B) can verify binding specificity . Additionally, tissue or cells from PEX11B knockout models, where available, provide the gold standard negative control for antibody validation.

How does PEX11B expression affect peroxisome dynamics and related gene expression?

PEX11B expression has profound effects on peroxisome dynamics and influences the expression of other peroxisomal genes through complex regulatory networks. Studies have shown that PEX11B promotes membrane protrusion and elongation on the peroxisomal surface, representing a critical early step in the peroxisome division process . This membrane remodeling function is essential for subsequent recruitment of division machinery, including the dynamin-related GTPase DNM1L, which facilitates the final scission events in peroxisome biogenesis . Research utilizing PEX11B knockdown approaches has demonstrated that reduced PEX11B expression significantly decreases the expression of multiple peroxisomal-related genes, including PEX1, PEX3, PMP70, PEX7, and ACOX1 . Interestingly, not all peroxisomal genes are equally affected, as PEX13 expression remained unchanged following PEX11B knockdown, suggesting specific regulatory relationships rather than global effects on peroxisomal gene expression . The peroxisome proliferation function of PEX11B appears to be conserved across various cell types and model organisms, indicating its fundamental role in organelle biogenesis.

What is the relationship between PEX11B and neural differentiation?

PEX11B plays a critical role in neural differentiation processes, with significant implications for developmental neurobiology research. Knockdown studies of PEX11B expression during neural differentiation of human embryonic stem cells have revealed that PEX11B is essential for proper formation of neural tube-like structures . When PEX11B expression is reduced through shRNA-mediated knockdown, a significant decrease in the expression of neural progenitor markers SOX1 and PAX6, as well as the neuronal marker TUJ1, is observed . The timing of these effects is developmentally regulated, with reduction in SOX1 and NESTIN expression levels observed primarily on day 14 during neural tube formation, while PAX6 expression continued to decrease throughout the differentiation period (through day 20) . These findings suggest a temporal specificity in PEX11B's role during neurogenesis. The connection between peroxisomal function and neural development is further supported by the observation that PEX11B knockdown affects the expression of multiple peroxisomal genes, including PEX1, PEX3, PMP70, PEX7, and ACOX1, indicating potential metabolic underpinnings for the observed developmental phenotypes .

What methodologies are effective for studying PEX11B function through genetic manipulation?

Genetic manipulation approaches provide powerful tools for investigating PEX11B function in various cellular contexts. Lentiviral vector systems have been successfully employed to introduce short hairpin RNA (shRNA) targeting PEX11B into human embryonic stem cells . Specifically, vectors such as pLVTHM and pLVPT-tTR-KRAB have been utilized to create doxycycline-inducible knockdown systems, allowing for temporal control of PEX11B suppression . For effective knockdown, doxycycline concentrations of approximately 750 ng/mL have been demonstrated to induce sufficient shRNA expression . Verification of successful knockdown should be performed at both the transcript level using qRT-PCR and at the protein level via Western blot analysis, with antibodies used at approximately 1:1000 dilution . When establishing stable cell lines, selection with appropriate antibiotics (such as blasticidin at 6 μg/mL) and confirmation of genomic insertion through PCR are critical validation steps . It is important to verify that stemness characteristics remain unchanged following genetic manipulation, which can be accomplished by monitoring expression levels of pluripotency markers such as NANOG and OCT4 .

What techniques are recommended for investigating PEX11B interactions with other peroxisomal proteins?

Investigating PEX11B interactions with other peroxisomal proteins requires specialized techniques that can capture both transient and stable protein-protein associations. Immunoprecipitation (IP) represents a primary approach, with several validated PEX11B antibodies being suitable for this application . The standard IP protocol involves cell lysis under mild conditions to preserve protein interactions, followed by antibody capture of PEX11B complexes and subsequent analysis of co-precipitated proteins. Western blot analysis of immunoprecipitated samples can identify specific interaction partners using antibodies against candidate proteins like DNM1L or other peroxisomal factors. For studying dynamic interactions in living cells, proximity ligation assays (PLA) or fluorescence resonance energy transfer (FRET) can be employed, requiring appropriate fluorescently tagged antibodies or fusion proteins. Mass spectrometry-based approaches following PEX11B immunoprecipitation can provide unbiased identification of interaction partners, which can be particularly valuable for discovering novel associations. Validation of identified interactions should include reciprocal co-immunoprecipitation experiments and ideally functional studies examining the consequences of disrupting specific interactions.

What are the optimal conditions for Western blot analysis using PEX11B antibodies?

Achieving optimal Western blot results with PEX11B antibodies requires careful attention to sample preparation and protocol conditions. For protein extraction, direct cell lysis in TRIzol reagent has been successfully employed in PEX11B studies, with protein content estimated using the Bradford method . Loading approximately 30 μg of total protein per lane on SDS-12% polyacrylamide gels provides sufficient material for detection while minimizing background . Transfer to PVDF membranes has been validated for PEX11B Western blots, with common antibody dilutions ranging from 1:500 to 1:1000 . The expected molecular weight of PEX11B is approximately 28 kDa, which should be confirmed with appropriate molecular weight markers . For detection, HRP-conjugated secondary antibodies used at dilutions around 1:5000 provide good signal-to-noise ratios . Validated positive control samples include MCF-7, Raw264.7, and PC12 cell lysates, which have been shown to express detectable levels of PEX11B . When encountering faint signals, optimization steps might include extending primary antibody incubation time (overnight at 4°C), increasing antibody concentration, or employing enhanced chemiluminescence (ECL) detection systems with longer exposure times.

How should immunohistochemistry protocols be optimized for PEX11B detection in different tissue types?

Immunohistochemistry (IHC) protocols for PEX11B detection require optimization for different tissue types to ensure specific and sensitive staining. For formalin-fixed, paraffin-embedded (FFPE) tissues, heat-induced epitope retrieval in citrate buffer (pH 6.0) or EDTA buffer (pH 9.0) should be evaluated to determine which provides optimal antigen recovery without increasing background staining. Validated PEX11B antibodies have been successfully used at dilutions of approximately 1:200 for IHC applications in human breast tissue . Blocking steps should include both protein blocking (using 5-10% normal serum from the species of the secondary antibody) and peroxidase blocking (using 0.3% hydrogen peroxide) to minimize non-specific staining. For visualization, both chromogenic detection (such as DAB) and fluorescence-based methods have been validated with PEX11B antibodies, though specific optimization may be required for each tissue type. When analyzing tissues with high lipid content (which often contain abundant peroxisomes), additional blocking with 0.1-0.3% Triton X-100 may improve specificity by reducing hydrophobic interactions. Control tissues should include both positive controls (tissues known to express PEX11B) and negative controls (either tissues from PEX11B knockdown/knockout models or sections treated with isotype control antibodies).

What are common troubleshooting approaches for inconsistent PEX11B antibody results?

When encountering inconsistent results with PEX11B antibodies, several systematic troubleshooting approaches can help identify and resolve the underlying issues. For weak or absent signals in Western blots, researchers should first verify protein loading using housekeeping controls like GAPDH and consider increasing antibody concentration, extending incubation times, or using more sensitive detection systems . Non-specific bands may indicate suboptimal blocking or antibody dilution, which can be addressed by increasing blocking agent concentration (to 5% BSA or milk) or further diluting the primary antibody. For immunohistochemistry applications, inconsistent staining might result from variations in fixation time or antigen retrieval conditions, requiring standardization of these parameters across samples. The stability of the antibody solution should be considered, as PEX11B antibodies are typically recommended to be stored at -20°C, with aliquoting advised to avoid freeze-thaw cycles that could compromise antibody integrity . When transferring protocols between different tissue types or cell lines, optimization of antibody concentration is often necessary, as expression levels and accessibility of epitopes can vary significantly. Finally, if inconsistencies persist across multiple experiments, validating the antibody with known positive and negative controls (such as PEX11B knockdown samples) is essential to confirm specificity .

What data validation approaches should be used when working with PEX11B antibodies?

Rigorous validation of data generated using PEX11B antibodies is essential for ensuring reliable and reproducible research findings. Multiple detection methods should be employed whenever possible, comparing results from different techniques such as Western blot, immunohistochemistry, and immunofluorescence to confirm consistent expression patterns. Quantitative analysis of Western blot bands should include normalization to appropriate loading controls like GAPDH, with statistical analysis performed across multiple biological replicates . Genetic manipulation approaches, such as shRNA-mediated knockdown of PEX11B, provide powerful validation tools by creating negative control samples with reduced target expression . Correlation of protein-level data (from antibody-based detection) with mRNA expression (from qRT-PCR or RNA-seq) can provide additional validation of expression patterns. When examining PEX11B localization, co-staining with established peroxisomal markers like PMP70 should be performed to confirm the expected subcellular distribution. For functional studies, complementary approaches such as gene knockdown and rescue experiments provide strong validation of observed phenotypes. Finally, when publishing results, detailed reporting of antibody information (catalog number, lot number, dilution, incubation conditions) is essential for research transparency and reproducibility.

What are the recommended storage and handling practices for maintaining PEX11B antibody performance?

Proper storage and handling of PEX11B antibodies is critical for maintaining their performance and extending their useful lifespan. Commercial PEX11B antibodies are typically supplied in liquid form, usually in PBS buffer containing preservatives such as 0.02% sodium azide and stabilizers like 50% glycerol . These antibodies should be stored at recommended temperatures, typically -20°C for long-term storage, where they remain stable for approximately one year after shipment . For antibodies stored in glycerol, aliquoting is generally unnecessary for -20°C storage, reducing the risk of contamination from repeated handling . When working with antibodies, it's important to avoid repeated freeze-thaw cycles, which can lead to protein denaturation and reduced activity. During experiments, antibodies should be kept on ice and returned to storage promptly after use. Some commercial preparations may contain carriers like BSA (0.1%) in smaller size formats (20 μl), which provides additional stability . Before each use, antibodies should be gently mixed (not vortexed) to ensure homogeneity without causing protein aggregation. Maintaining sterile technique when handling antibody solutions helps prevent microbial contamination that could degrade the antibody or introduce experimental artifacts. Following these storage and handling practices will help ensure consistent antibody performance across experiments and maximize the useful lifespan of these valuable research reagents.

PEX11B Antibody Applications and Recommended Conditions

Effect of PEX11B Knockdown on Gene Expression

Common Troubleshooting Issues and Solutions for PEX11B Antibody Applications