SAMDC2 Antibody
Description
Definition and Biological Context
SAMDC2 Antibody refers to an immunological reagent targeting S-Adenosylmethionine Decarboxylase 2 (SAMDC2), a key enzyme in polyamine biosynthesis. SAMDC2 catalyzes the conversion of S-adenosylmethionine (SAM) to decarboxylated SAM, which is essential for synthesizing spermidine and spermine—critical polyamines for cell proliferation, differentiation, and stress response .
Gene and Protein Characteristics
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Gene: SAMDC2 (human homolog of Caenorhabditis elegans SAMDC) is located on chromosome 17q25.3 .
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Protein: SAMDC2 exists as a proenzyme (42 kDa) that undergoes autocatalytic cleavage to form α- and β-subunits (32 kDa and 10 kDa, respectively) .
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Catalytic Activity: Requires a pyruvoyl cofactor for decarboxylation .
Key Functional Domains
| Domain | Role |
|---|---|
| N-terminal | Proenzyme cleavage site |
| Catalytic core | Pyruvoyl-binding active site |
| C-terminal | Substrate specificity region |
Research Applications
SAMDC2 antibodies are critical for:
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Western Blot: Detecting SAMDC2 in lysates (e.g., human cell lines, rat liver) .
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Immunohistochemistry (IHC): Localizing SAMDC2 in paraffin-embedded tissues (e.g., human appendix) .
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Immunofluorescence (IF): Visualizing subcellular distribution (e.g., HeLa cells) .
Example Protocol (IHC):
"After dewaxing, antigen retrieval was performed via high-pressure citrate buffer. Sections were blocked with 10% goat serum, incubated with SAMDC2 antibody (1:600), and detected using biotinylated secondary antibodies" .
Role in Disease
SAMDC2 is implicated in:
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Cancer: Elevated polyamine levels in tumors correlate with SAMDC2 overexpression .
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Neurodegenerative Disorders: Dysregulated polyamine metabolism in Alzheimer’s and Parkinson’s diseases .
Monoclonal Antibody Development
| Target | Application | Mechanism | Example Antibody |
|---|---|---|---|
| SAMDC2 | Cancer therapy | Inhibits polyamine synthesis | Preclinical |
| Viral infections | Antiviral therapy | Blocks viral replication | Under study |
Key Products
| Supplier | Product Code | Host | Applications | Validation Data |
|---|---|---|---|---|
| Abcam | ab237681 | Rabbit | WB, IHC, ICC/IF | Rat liver lysate |
| Sigma-Aldrich | HPA024634 | Rabbit | IHC, IF | Human Protein Atlas |
Validation Criteria:
Challenges and Future Directions
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Specificity Issues: SAMDC2 shares homology with SAMDC1, necessitating rigorous validation .
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Therapeutic Potential: Antibody-drug conjugates (ADCs) targeting SAMDC2 are under exploration for oncology .
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Biomarker Development: Correlating SAMDC2 levels with disease progression in longitudinal studies .
Key Research Findings
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Dynamic Expression: SAMDC2 levels fluctuate during cell cycle phases, peaking in S-phase .
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Regulatory Mechanisms: The 5’-UTR of SAMDC2 mRNA contains a small upstream ORF regulating translation .
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In Vivo Models: SAMDC2-knockout mice exhibit embryonic lethality, underscoring its developmental role .
References
Product Specs
Target Background
Q&A
Advanced Experimental Design Challenges
How to resolve contradictions in SAMDC stability assays?
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Troubleshooting: Include HY5 protein controls to verify assay specificity, as SAMDC1 stabilization by C2 is unique compared to other proteasome substrates ( ).
How to design studies analyzing SAMDC’s dual roles in polyamine biosynthesis and gene silencing?
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Use split-ubiquitin yeast assays to map interaction domains between SAMDC and viral proteins.
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Apply CRISPR-Cas9-mediated point mutations to residues critical for decarboxylase activity (e.g., His-87 in SAMDC1) and assess impacts on viral DNA methylation.
Methodological Considerations for Antibody Applications
What controls are essential for SAMDC antibody validation in epigenetic studies?
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Negative: samdc1 mutant plant extracts.
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Competition: Pre-incubate antibodies with recombinant SAMDC1 protein (50 µg/mL for 1 hr) to block epitope binding.
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Cross-reactivity: Test against SAMDC paralogs (e.g., SAMDC2/3) via Western blot (if available).
How to optimize SAMDC antibody use in protein degradation assays?
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Time-course Western blots: Sample every 30 minutes post-cycloheximide treatment.
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Buffer optimization: Include 10 mM N-ethylmaleimide to inhibit deubiquitinases and preserve ubiquitinated SAMDC forms.
