CTSD Antibody
Product Specs
Q&A
Basic Research Questions
How to validate CTSD antibody specificity across Western blot (WB), immunohistochemistry (IHC), and flow cytometry?
Validation requires multi-modal testing:
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Epitope mapping: Use recombinant CTSD or knockout cell lysates to confirm target recognition .
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Cross-reactivity assessment: Test against related proteases (e.g., cathepsin E, pepsin A) using ELISA or immunoprecipitation .
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Application-specific optimization: For flow cytometry, validate with isotype controls and titration to minimize background (e.g., 1–5 µg/mL primary antibody concentration) .
Example validation data:
| Assay | Signal-to-Noise Ratio | Cross-Reactivity Tested Proteins |
|---|---|---|
| WB | >10:1 | CTSE, Pepsin A, Renin |
| IHC | >8:1 | THBS2, THBS3, THBS4 |
| Flow | >5:1 | Isotype control (rabbit IgG) |
What pre-analytical variables most significantly impact CTSD quantification in serum/plasma?
Key factors include:
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Sample handling: Prolonged room-temperature storage (>4 hours) reduces CTSD stability .
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Centrifugation: Use 2,000–3,000 ×g for 10–15 min at 4°C to prevent platelet contamination .
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Storage: Serum retains 80–120% CTSD recovery after 6 months at -80°C .
How to resolve discrepancies in subcellular localization studies of CTSD?
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Fractionation controls: Validate lysosomal (intracellular) vs. extracellular fractions using markers like LAMP1 (lysosomes) or albumin (extracellular) .
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Inhibitor-based profiling: Use GA-12 (intracellular inhibitor) and CTD-002 (extracellular inhibitor) to isolate compartment-specific activity .
Advanced Research Questions
How does extracellular CTSD inhibition differentially affect metabolic inflammation compared to intracellular inhibition?
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Mechanistic divergence:
Therapeutic implications:
| Parameter | CTD-002 (Extracellular) | GA-12 (Intracellular) |
|---|---|---|
| Hepatic steatosis | ↓45% | ↔ |
| TNFα expression (BMDMs) | ↓60% | ↔ |
| Toxicity | Low | Moderate |
How to design multiplex assays integrating CTSD with complementary biomarkers (e.g., THBS1) for cancer diagnostics?
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Assay compatibility: Use orthogonal detection systems (e.g., CTSD via ELISA, THBS1 via electrochemiluminescence) to avoid cross-talk .
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Data normalization: Apply Lot-to-lot correction factors (≤15% variance) and inter-laboratory calibration .
What strategies address contradictory reports on CTSD’s pro-tumor vs. tumor-suppressive roles?
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Context-specific analysis:
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Functional studies: Use CRISPR-Cas9 knockout models to isolate CTSD-dependent pathways in tumor microenvironments.
Methodological Best Practices
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Antibody lot validation: Include ≥3 independent lots in precision studies (total CV ≤10%) .
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Dynamic range optimization: For ELISA, use 1:41–1:1,681 serum dilutions to avoid hook effects .
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Data contradiction resolution: Pair transcriptomics (qRT-PCR for CTSD) with functional proteomics (activity assays) to reconcile discordant findings .
Product Science Overview
Cathepsin D is a lysosomal aspartyl protease encoded by the CTSD gene in humans . It is ubiquitously distributed in lysosomes and plays a crucial role in the degradation of proteins within the cell . Cathepsin D is involved in various physiological processes, including protein catabolism, hormone processing, and the activation of precursor proteins . It is also implicated in several pathological conditions, such as Alzheimer’s disease, cancer, and neurodegenerative disorders .
Cathepsin D is synthesized as an inactive precursor, known as preprocathepsin D, which undergoes proteolytic cleavage to form the active enzyme . The active enzyme consists of a protein dimer of disulfide-linked heavy and light chains . Cathepsin D functions optimally in the acidic environment of lysosomes and is involved in the degradation of various substrates, including amyloid-β protein (Aβ) and tau protein .
Cathepsin D has been extensively studied in the context of Alzheimer’s disease (AD). It degrades both the amyloid-β protein (Aβ) and the microtubule-associated protein tau, which accumulate pathognomonically in AD . Studies have shown that genetic deletion of Cathepsin D in mice leads to increased cerebral Aβ and tau pathology, suggesting a critical role for Cathepsin D in the proteostasis of these proteins . The enzyme’s activity is also influenced by Aβ42, which acts as a competitive inhibitor, further linking Cathepsin D to AD pathology .
Mouse anti-human Cathepsin D antibodies are commonly used in research to study the expression and function of Cathepsin D in various biological contexts. These antibodies are typically generated by immunizing mice with human Cathepsin D protein, followed by the isolation and purification of specific antibodies from the mouse serum. The antibodies can be used in various applications, including Western blotting, immunohistochemistry, and enzyme-linked immunosorbent assays (ELISA), to detect and quantify Cathepsin D in biological samples.
