Recombinant Bovine Cysteine protease ATG4B (ATG4B)
Product Specs
Note: We will prioritize shipping the format currently in stock. If you require a specific format, please specify this in your order notes, and we will accommodate your request.
Note: All proteins are shipped with standard blue ice packs unless otherwise requested. Dry ice shipping requires prior arrangement and incurs additional charges.
Generally, liquid formulations have a 6-month shelf life at -20°C/-80°C. Lyophilized formulations have a 12-month shelf life at -20°C/-80°C.
Target Background
Q&A
FAQs for Researchers on Recombinant Bovine Cysteine Protease ATG4B (ATG4B)
Advanced Research Questions
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How do redox modifications regulate ATG4B activity, and how can this be experimentally dissected?
ATG4B activity is reversibly inhibited by oxidation at Cys292 and Cys361, forming intramolecular disulfide bonds.
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Approach:
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Treat recombinant ATG4B with H₂O₂ (oxidizing agent) or DTT (reducing agent) and assay proteolytic activity .
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Use site-directed mutagenesis (e.g., C292S/C361S) to create redox-insensitive variants. These mutants retain activity under oxidative stress .
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Monitor autophagic flux in redox-insensitive mutant cells via LC3-II turnover under H₂O₂ exposure .
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How do conflicting reports on ATG4B’s role in cancer biology arise, and how can researchers address them?
ATG4B shows context-dependent roles: pro-survival in colorectal cancer vs. growth-inhibitory in triple-negative breast cancer .
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Resolution strategies:
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Cell line specificity: Compare ATG4B inhibition effects across cancer subtypes (e.g., HER2+ vs. HER2– breast cancer) .
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Autophagy-independent pathways: Use transcriptomics/proteomics to identify non-canonical ATG4B interactors (e.g., HER2) .
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In vivo validation: Test ATG4B inhibitors (e.g., LV-320) in xenograft models of divergent cancer types .
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What structural features of ATG4B determine substrate specificity for LC3 vs. GABARAP proteins?
The C-terminal LC3-interacting region (LIR) motif (residues 393–396) is critical:
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Experimental proof:
Data Tables
Table 1: Redox regulation of ATG4B activity
| Condition | ATG4B Activity | LC3-II Levels | Citation |
|---|---|---|---|
| H₂O₂ (oxidative) | Inhibited | Increased | |
| DTT (reductive) | Activated | Decreased | |
| C292,361S mutant | Constitutively active | Stable |
Table 2: ATG4B inhibitors and their mechanisms
| Compound | Target Site | IC₅₀ (μM) | Cellular Effect |
|---|---|---|---|
| LV-320 | Catalytic cleft | 0.8 | Blocks autophagic flux |
| NSC185058 | LIR motif | 5.2 | Reduces GABARAP binding |
