elo-4 Antibody

What is ELOVL4 protein and what biological functions does it mediate?

ELOVL4 (Elongation of Very Long Chain Fatty Acids Protein 4) is a transmembrane protein that functions as a key enzyme in very long chain fatty acid (VLC-FA) biosynthesis. This 37 kDa protein is primarily expressed in retinal tissue with lower expression levels in brain, thymus, testis, small intestine, ovary, and prostate, while minimal expression occurs in heart, lung, liver, or leukocytes . ELOVL4 catalyzes the rate-limiting condensation reaction in the elongation pathway, specifically converting 26:0 to 28:0 fatty acids and potentially mediating additional elongation steps for other VLC-FAs . The protein contains three critical functional motifs: an N-glycosylation consensus site at the N-terminus that likely aids proper folding and structural stability; a histidine-rich motif (HXXHH) that acts as the active site, proposed to chelate iron for electron transfer during O₂-dependent redox reactions; and a dilysine ER retention motif at the C-terminus that localizes ELOVL4 to the endoplasmic reticulum . Mutations in the ELOVL4 gene are associated with autosomal dominant Stargardt-like macular dystrophy (STGD3), highlighting its critical role in retinal function and maintenance .

What are the key specifications and applications of ELOVL4 antibodies?

ELOVL4 antibodies are essential tools for studying this protein's expression, localization, and function in both normal physiology and disease states. Commercial ELOVL4 antibodies, such as the rabbit polyclonal antibody catalog #AF0604, are typically raised against specific epitopes of the human ELOVL4 protein . These antibodies demonstrate reactivity with human and mouse ELOVL4, with predicted cross-reactivity to pig, bovine, horse, sheep, rabbit, dog, and chicken homologs based on sequence conservation . The primary research applications for ELOVL4 antibodies include Western blotting (WB) for detection of denatured protein samples and immunofluorescence/immunocytochemistry (IF/ICC) for cellular localization studies . For Western blotting applications, researchers have successfully utilized C-terminal-specific antibodies (C-ELOVL4) at 1:1,000 dilution to detect both tagged and untagged ELOVL4 proteins . When selecting an ELOVL4 antibody, researchers should consider the specific experimental requirements, including the species being studied, detection method, and whether native or denatured protein will be analyzed.

How are ELOVL4 antibodies validated for research applications?

Validation of ELOVL4 antibodies requires multiple complementary approaches to ensure specificity and reliability in experimental applications. Researchers have validated ELOVL4 antibodies through expression systems where cells are transduced with adenoviral constructs carrying ELOVL4 coding sequences, followed by Western blot analysis comparing antibody detection between transduced and untransduced control cells . Another validation approach involves comparing antibody reactivity in tissues known to express ELOVL4 at different levels, such as high expression in retina versus low expression in brain tissue . Epitope mapping through the use of truncated or mutated ELOVL4 constructs helps determine the specific binding region of the antibody, which is particularly important when studying mutations associated with diseases like STGD3 . For antibodies targeting specific post-translational modifications, validation includes treatment with appropriate enzymes (e.g., glycosidases for N-glycosylation sites) to demonstrate specificity . Researchers should always include appropriate positive and negative controls when using ELOVL4 antibodies, and ideally compare results across multiple antibodies targeting different epitopes to confirm specificity of detection.

What are the optimal protocols for using ELOVL4 antibodies in Western blotting?

When conducting Western blot analysis with ELOVL4 antibodies, researchers should optimize several parameters to ensure reliable and specific detection. Sample preparation begins with efficient cell lysis using buffers containing appropriate detergents (typically 1% Triton X-100 or NP-40) and protease inhibitors to prevent degradation of the target protein. Protein samples should be denatured at 95°C for 5 minutes in Laemmie buffer containing SDS and β-mercaptoethanol to disrupt protein structure and expose epitopes. For optimal separation of ELOVL4 (37 kDa), 10-12% SDS-PAGE gels are recommended, with running conditions of 100-120V for approximately 1.5 hours . Transfer to PVDF membranes is typically performed at 100V for 60-90 minutes in transfer buffer containing 20% methanol. Blocking with 5% non-fat dry milk or BSA in TBST for 1 hour at room temperature helps reduce non-specific binding. The ELOVL4 antibody should be diluted to 1:1,000 in blocking buffer and incubated overnight at 4°C for optimal binding . After thorough washing with TBST (at least 3 × 10 minutes), appropriate HRP-conjugated secondary antibodies should be applied at 1:5,000 dilution for 1 hour at room temperature. Following additional washing steps, detection can be performed using enhanced chemiluminescence (ECL) reagents with exposure times optimized for the specific signal intensity.

How should researchers approach ELOVL4 antibody selection for immunofluorescence studies?

For immunofluorescence applications studying ELOVL4, antibody selection should prioritize reagents specifically validated for this technique. Researchers should begin by examining the antibody datasheet for documented IF/ICC applications and representative images demonstrating proper subcellular localization to the endoplasmic reticulum, consistent with ELOVL4's known biological distribution . When designing IF experiments, cells should be fixed with 4% paraformaldehyde for 15-20 minutes at room temperature, followed by permeabilization with 0.1-0.2% Triton X-100 for 10 minutes to facilitate antibody access to intracellular antigens. Blocking with 5% normal serum (matching the species of the secondary antibody) for 30-60 minutes reduces non-specific binding. ELOVL4 antibodies should be applied at experimentally determined dilutions (typically 1:100 to 1:500) and incubated overnight at 4°C in a humidified chamber . For co-localization studies, combining ELOVL4 antibodies with markers for the endoplasmic reticulum such as anti-calnexin antibodies provides valuable confirmation of proper localization . When analyzing results, researchers should be aware that mutations in ELOVL4, particularly those affecting the C-terminal ER retention motif, can dramatically alter cellular localization patterns, potentially requiring different fixation and permeabilization protocols for optimal detection.

What controls are essential when using ELOVL4 antibodies in research?

Implementing appropriate controls is critical for meaningful interpretation of experiments utilizing ELOVL4 antibodies. Positive controls should include samples known to express ELOVL4, such as retinal tissue or cell lines with confirmed ELOVL4 expression . Conversely, negative controls should utilize tissues or cells with minimal ELOVL4 expression like leukocytes or liver tissue, or those where ELOVL4 has been knocked down through siRNA or CRISPR-Cas9 methods . For antibody specificity controls, pre-incubation of the antibody with its immunizing peptide (peptide blocking) should abolish specific staining in Western blot or immunofluorescence applications. When studying mutant forms of ELOVL4, wild-type constructs should be run in parallel to demonstrate differential binding or localization patterns . Technical controls should include secondary-only controls (omitting primary antibody) to assess non-specific binding of the secondary antibody and isotype controls using non-specific IgG from the same species as the primary antibody at equivalent concentration . For quantitative applications, researchers should include loading controls such as β-actin for Western blotting or nuclear counterstains for immunofluorescence to normalize results across samples . Establishing these controls ensures experimental rigor and facilitates accurate interpretation of results when working with ELOVL4 antibodies.

How can ELOVL4 antibodies be used to study mutations associated with Stargardt-like macular dystrophy?

ELOVL4 antibodies serve as powerful tools for investigating the molecular mechanisms underlying Stargardt-like macular dystrophy (STGD3), a condition linked to mutations in the ELOVL4 gene. Researchers can generate cell models expressing wild-type or mutant ELOVL4 using plasmid constructs and adenoviral vectors, as demonstrated in previous studies where mouse Elovl4 (both wild-type and 5-bp deletion mutants) were expressed with hemagglutinin (HA) tags for detection . Western blot analysis using C-terminal-specific ELOVL4 antibodies can reveal differences in protein expression, stability, and post-translational modifications between wild-type and disease-associated mutants . Immunofluorescence microscopy with ELOVL4 antibodies allows visualization of altered subcellular localization patterns, as mutations affecting the C-terminal ER retention motif may disrupt proper localization to the endoplasmic reticulum. Co-immunoprecipitation experiments using ELOVL4 antibodies can identify altered protein-protein interactions resulting from disease-causing mutations. For functional studies, researchers can combine ELOVL4 antibody-based protein detection with lipid analysis techniques to correlate changes in protein expression or localization with alterations in very long chain fatty acid production, particularly the conversion of 26:0 to 28:0 fatty acids that ELOVL4 mediates .

What approaches enable studying the role of ELOVL4's histidine-rich motif using antibodies?

The histidine-rich motif (HXXHH) in ELOVL4 represents a critical active site for the protein's enzymatic function in fatty acid elongation, and antibody-based techniques can help elucidate its role. Site-directed mutagenesis approaches, where individual histidines are mutated to glutamines (as described in the literature), can be combined with antibody detection to correlate structural changes with functional outcomes . Researchers can generate a panel of ELOVL4 mutants with single or combined histidine substitutions, express them in appropriate cell systems, and then use Western blotting with anti-ELOVL4 antibodies to confirm equivalent expression levels across constructs. Immunofluorescence with ELOVL4 antibodies can verify proper subcellular localization of the mutant proteins, ensuring that any observed functional deficits are not due to mislocalization. Co-immunoprecipitation experiments using ELOVL4 antibodies can determine whether histidine mutations affect interactions with other elongation machinery components. Functional assays measuring the conversion of 26:0 to 28:0 fatty acids can be correlated with antibody-detected protein levels to calculate specific activity of each histidine mutant. By combining these approaches with structural modeling, researchers can develop a comprehensive understanding of how the histidine-rich motif contributes to ELOVL4's catalytic mechanism and substrate specificity.

How can researchers investigate the N-glycosylation of ELOVL4 using specialized antibody techniques?

ELOVL4 contains an N-glycosylation consensus site (NDTV) at its N-terminus that likely contributes to proper folding and stability . To investigate this post-translational modification, researchers can employ several antibody-based approaches. Western blot analysis comparing untreated samples with those treated with glycosidases (such as PNGaseF or Endoglycosidase H) can reveal mobility shifts indicating the presence and type of N-glycosylation on ELOVL4. Site-directed mutagenesis of the consensus site (for example, changing NDTV to NDAV as mentioned in the literature) followed by antibody detection can demonstrate the functional consequences of preventing glycosylation . Researchers can use lectin affinity chromatography in conjunction with ELOVL4 antibody detection to isolate and characterize the glycosylated forms of the protein. For evaluating the impact of glycosylation on protein stability, pulse-chase experiments with radiolabeled amino acids followed by immunoprecipitation with ELOVL4 antibodies can determine if non-glycosylated mutants have altered half-lives compared to wild-type protein. To assess effects on localization, dual-label immunofluorescence can be performed using antibodies against ELOVL4 and ER markers, comparing wild-type and glycosylation-deficient mutants. These approaches collectively enable a comprehensive assessment of how N-glycosylation influences ELOVL4's structure, stability, localization, and ultimately its function in very long chain fatty acid elongation.

What strategies can resolve non-specific binding issues with ELOVL4 antibodies?

Non-specific binding is a common challenge when working with ELOVL4 antibodies that can compromise experimental interpretation. To mitigate this issue, researchers should first optimize the antibody concentration through titration experiments, testing dilutions ranging from 1:100 to 1:5,000 to identify the optimal signal-to-noise ratio for their specific application. Enhancing blocking protocols by increasing blocking agent concentration (up to 10% normal serum or BSA), extending blocking duration (2-3 hours at room temperature), or using alternative blocking agents (such as commercial blocking buffers containing various proteins and detergents) can significantly reduce background. Including additional washing steps with higher detergent concentrations (up to 0.3% Tween-20 in TBST) and extending wash durations may help eliminate weakly bound antibodies. For Western blotting applications, pre-adsorption of the antibody with membrane extracts from cells not expressing ELOVL4 can deplete cross-reactive antibodies from polyclonal preparations. In tissues with high autofluorescence (particularly retinal tissue where ELOVL4 is highly expressed), treatment with sodium borohydride or Sudan Black B prior to antibody application can reduce background. If persistent non-specific binding occurs despite these measures, switching to a monoclonal ELOVL4 antibody or an antibody targeting a different epitope may resolve specificity issues.

How can researchers optimize ELOVL4 antibody-based protein quantification?

Accurate quantification of ELOVL4 protein levels requires careful experimental design and rigorous methodology. For Western blot-based quantification, researchers should establish a standard curve using recombinant ELOVL4 protein at known concentrations to ensure measurements fall within the linear detection range of the antibody. Sample loading should be standardized based on total protein concentration determined by BCA or Bradford assay rather than relying solely on housekeeping proteins, which may vary across experimental conditions. Digital image acquisition using CCD camera-based systems provides superior quantitative data compared to film-based detection, with exposure times optimized to avoid pixel saturation. Normalization strategies should include multiple housekeeping proteins (such as β-actin, GAPDH, and tubulin) to account for potential variability . For immunofluorescence-based quantification, researchers should maintain consistent image acquisition parameters across all samples, including exposure time, gain, and offset settings. Z-stack acquisition followed by maximum intensity projection can improve signal detection while maintaining quantitative accuracy. Automated image analysis using software like ImageJ or CellProfiler enables objective quantification of ELOVL4 signal intensity, which can be normalized to cell number using nuclear counterstains. When comparing data across multiple experiments, researchers should include internal reference standards on each blot or slide to account for day-to-day variability in antibody performance.

What approaches help distinguish between closely related ELOVL family members?

Distinguishing ELOVL4 from other ELOVL family members (ELOVL1-7) presents a significant challenge due to sequence homology and functional similarity. Researchers should begin by carefully selecting ELOVL4 antibodies raised against unique regions of the protein, particularly the C-terminus, which shows greater sequence divergence among family members . Antibody specificity should be validated using overexpression systems where individual ELOVL proteins are expressed in cell lines, followed by Western blotting to confirm selective detection of ELOVL4. For tissues expressing multiple ELOVL proteins, comparative analysis using knockout or knockdown models for ELOVL4 can confirm antibody specificity. Immunoprecipitation followed by mass spectrometry can provide definitive identification of the immunoprecipitated protein as ELOVL4 rather than other family members. When analyzing ELOVL4 function, complementary approaches targeting unique substrates can help distinguish its activity from other family members; for example, ELOVL4's specific role in converting 26:0 to 28:0 fatty acids can be measured distinct from the activities of other ELOVLs . Combining antibody-based protein detection with RT-qPCR analysis of ELOVL4 mRNA provides correlative evidence strengthening identification. In cases where absolute specificity cannot be guaranteed, researchers should acknowledge potential cross-reactivity in their experimental interpretations and consider complementary non-antibody approaches to confirm ELOVL4-specific findings.

How does ELOVL4 antibody methodology compare with approaches for studying Elotuzumab (anti-SLAMF7)?

While both ELOVL4 antibodies and Elotuzumab target distinct proteins, comparing their research methodologies reveals important technical considerations. ELOVL4 antibodies typically target an intracellular enzyme involved in fatty acid metabolism and require cell permeabilization for access to their epitopes in immunofluorescence applications . In contrast, Elotuzumab targets SLAMF7 (CD319), a cell surface glycoprotein on multiple myeloma cells and natural killer (NK) cells, allowing direct detection of intact cells without permeabilization . Flow cytometry represents a primary analytical technique for Elotuzumab studies, with antibodies like anti-human CD319 (SLAMF7, CRACC: clone 162.1)-APC used to measure surface expression on different cell populations . For ELOVL4, Western blotting and immunofluorescence are the predominant analytical methods . Functional assays also differ significantly: ELOVL4 antibodies primarily serve detection purposes, while Elotuzumab possesses intrinsic therapeutic activity through antibody-dependent cellular cytotoxicity (ADCC) that can be measured using reporter bioassays or cytotoxicity assays with target and effector cells . When evaluating specificity, ELOVL4 antibodies are typically validated against recombinant proteins or knockout models, whereas Elotuzumab specificity can be assessed through competitive binding with known SLAMF7 ligands or by comparing binding to SLAMF7-positive versus negative cell lines .

What technical considerations differentiate working with research-grade versus therapeutic antibodies?

Research-grade antibodies like those targeting ELOVL4 differ substantially from therapeutic antibodies like Elotuzumab in several important technical aspects. Research antibodies typically undergo validation focused on specific laboratory applications (Western blotting, immunofluorescence) rather than the extensive preclinical and clinical testing required for therapeutic antibodies . Production scale and quality control standards are substantially different, with research antibodies often produced in smaller batches with batch-to-batch variability, while therapeutic antibodies require consistent, large-scale GMP production with stringent quality controls . Formulation represents another key difference: research antibodies are typically supplied in simple buffers with preservatives suitable for laboratory storage but not for in vivo administration, whereas therapeutic antibodies require specialized formulations ensuring stability, sterility, and compatibility with biological systems . Research antibodies may be polyclonal (containing mixed antibody populations) or monoclonal, with polyclonal offering broader epitope recognition but greater variability; therapeutic antibodies like Elotuzumab are exclusively monoclonal, providing consistent epitope targeting . When conducting research with therapeutic antibodies, investigators must consider additional factors including Fc effector functions (ADCC, complement activation), which may contribute to observed experimental effects beyond simple target binding .