Description

Glutamyl endopeptidase (EC 3.4.21.19), also known as asparaginyl endopeptidase or V8 protease, belongs to the serine protease family. It is derived from Staphylococcus aureus and is often referred to as Staphylococcus aureus V8 protease. This product is recombinantly expressed in E. coli and purified through multi-step chromatography. It specifically recognizes and hydrolyzes peptide bonds at the carboxyl-terminal of glutamate or aspartate residues.

• In NH₄HCO₃ buffer (pH 7.8) or CH₃COONH₄ buffer (pH 4.0), it cleaves peptide bonds at the carboxyl-terminal of glutamate residues.

• In phosphate buffer (pH 7.8), it hydrolyzes both glutamate and aspartate carboxyl-terminal peptide bonds, with a higher cleavage rate for glutamate bonds.

The enzyme is active across a pH range of 4.0–10.0, with an optimal reaction pH of 8.0–8.5. Originally used for insulin peptide mapping, it has since been widely applied in protein sequence analysis. It can be used independently or combined with other proteases for peptide mapping and protein identification via peptide mass fingerprinting.

Quality Parameters

• Appearance: White or off-white lyophilized powder
• Content: 80%–120% of labeled amount 
• Electrophoretic Purity: ≥95%
• Molecular Weight: 24kDa ± 2.4kDa
• Specific Activity: ≥5.0 AU/mg

Notes: 

① Labeled amount refers to packaging specifications. Larger packaging sizes can be customized upon request. 

② Enzyme activity definition: One activity unit (AU) is defined as the amount of enzyme required to catalyze the production of 1μmol of 4-nitroaniline per minute at 37°C in a pH 8.0 buffer with the substrate Z-Phe-Leu-Glu-4-nitroanilide.

Recommended Usage

• Dissolution Buffer: Sterile water or 50mmol/L Tris-HCl, pH 8.0.
• Digestion Buffer: 50mmol/L Tris-HCl, 2mmol/L CaCl₂, pH 8.0.
• Recommended Conditions: Use at a protease-to-protein ratio of 1:20–1:100.

Storage

• Storage Stability: Lyophilized powder should be stored below -15°C. Once dissolved in 50mmol/L Tris-HCl buffer (pH 8.0), it retains over 85% activity when stored at 25°C or 37°C overnight (15 hours). Long-term stability data is forthcoming.
• Transport Stability: Shipped with ice packs to maintain activity without loss.