COQ5 Antibody
Description
Overview of COQ5 Antibody
COQ5 (coenzyme Q5 homolog, methyltransferase) is a mitochondrial enzyme essential for the methylation step in CoQ10 biosynthesis. The COQ5 antibody is a rabbit polyclonal IgG generated against recombinant COQ5 protein, enabling detection of both precursor and mature forms of COQ5 in human and mouse tissues . Key characteristics include:
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Target: COQ5 protein (UniProt ID: Q5HYK3).
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Reactivity: Human, mouse, and rat (species-dependent validation) .
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Immunogen: Recombinant COQ5 protein (amino acid sequence derived from NM_032314) .
Research Applications and Validation Data
COQ5 antibodies are widely used to investigate CoQ10 biosynthesis and mitochondrial dysfunction. Validation data from multiple sources confirm their utility:
Table 1: Applications and Recommended Dilutions
Table 2: Tissue Reactivity in IHC
Clinical and Pathological Relevance
COQ5 dysfunction is linked to primary CoQ10 deficiency, a condition associated with cerebellar ataxia, encephalopathy, and mitochondrial disorders . Key findings include:
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Genetic Mutations: Loss-of-function mutations in COQ5 reduce CoQ10 levels in blood and muscle, leading to neurometabolic defects .
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Therapeutic Response: CoQ10 supplementation improves clinical outcomes in patients with COQ5 mutations, underscoring the protein’s role in cellular energy metabolism .
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Mitochondrial Localization: COQ5 is localized to the mitochondrial inner membrane, and its maturation is suppressed under conditions of chemical uncoupling, directly impacting CoQ10 synthesis .
Product Specs
Constituents: 50% Glycerol, 0.01M Phosphate Buffered Saline (PBS), pH 7.4
Target Background
Q&A
FAQs for COQ5 Antibody in Academic Research
What experimental strategies address discrepancies in COQ5 detection across tissue types?
Advanced Research Considerations:
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Tissue-Specific Isoforms: COQ5 has multiple mRNA splice variants. Use isoform-specific primers in qRT-PCR (e.g., amplifying exons 3–5) and validate with isoform-selective antibodies .
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Post-Translational Modifications: Mitochondrial proteases may cleave COQ5 precursors. Use antibodies recognizing both precursor (~40 kDa) and mature (~34 kDa) forms, as seen in uncoupler-treated cells .
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Buffer Optimization: For WB, employ mitochondrial lysis buffers with 1% Triton X-100 to solubilize membrane-associated COQ5 .
How does COQ5 antibody facilitate mechanistic studies of CoQ10 deficiency disorders?
Experimental Design:
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Patient-Derived Models: Use COQ5 antibodies to compare protein levels in fibroblasts from patients with cerebellar ataxia vs. controls. Quantify CoQ10 via HPLC alongside WB analysis .
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Rescue Experiments: Transfect mutant COQ5 yeast with human COQ5 and monitor rescue of respiratory growth and CoQ6 levels. Antibody confirms human COQ5 expression in yeast mitochondria .
Key Finding:
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COQ5 mutations reduce CoQ10 levels in leukocytes (60% of controls) and muscle (30% of controls), reversible with CoQ10 supplementation .
What controls are critical for co-immunoprecipitation (co-IP) of COQ5 interactors?
Methodological Rigor:
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Negative Controls:
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Crosslinker Optimization: For transient interactions (e.g., within the CoQ-synthome), use formaldehyde crosslinking before lysis .
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Validation: Confirm co-purified partners (e.g., COQ4) via WB and mass spectrometry .
How to resolve contradictory data on COQ5’s catalytic activity in heterologous systems?
Advanced Analysis:
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Species-Specific Complementation: Human COQ5 rescues yeast coq5 point mutants (e.g., coq5-2) but requires COQ8 overexpression in null mutants, suggesting dependency on CoQ-synthome assembly .
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Enzyme Assays: Measure methyltransferase activity using radiolabeled S-adenosyl methionine (SAM) and demethoxy-Q intermediates. Human COQ5 shows 40% activity compared to yeast Coq5 in vitro .
Data Table: Functional Rescue in Yeast
| Yeast Strain | Human COQ5 Expression | CoQ6 Level (% Wild-Type) |
|---|---|---|
| coq5-2 mutant | Yes | 75% |
| coq5Δ | Yes + COQ8 OE | 50% |
What orthogonal methods confirm COQ5 antibody specificity in high-throughput screens?
Multi-Omics Integration:
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CRISPR-Cas9 Knockout: Use COQ5-KO cell lines (e.g., HEK293) to verify loss of signal in WB/IHC .
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Parallel Reaction Monitoring (PRM): Quantify COQ5 peptides (e.g., VLEDGVK) via mass spectrometry alongside antibody-based assays .
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Epitope Mapping: Compare antibody binding to truncated COQ5 variants expressed in E. coli .
How to optimize COQ5 detection in archival clinical samples?
Technical Adjustments:
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Antigen Retrieval: For FFPE tissues, use pH 9.0 Tris-EDTA buffer (superior to citrate pH 6.0 for COQ5 epitopes) .
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Signal Amplification: Employ tyramide-based amplification in IHC for low-abundance COQ5 in neurodegenerative disease brain sections .
What computational tools predict COQ5-antibody cross-reactivity?
Bioinformatics Workflow:
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Epitope BLAST: Align immunogen sequence (e.g., residues 220–249) against proteomes of common model organisms.
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Structural Modeling: Use AlphaFold-predicted COQ5 structure to assess surface accessibility of the epitope .
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Experimental Cross-Reactivity: Test antibody against mitochondrial lysates from mouse, rat, and human (see for species-specific validation).
