Immunomodulating metalloprotease (IMPa)*
Product summary
IMPa is a broad-specificity metalloprotease that selectively cleaves peptide bonds on the N-terminal side of serine or threonine residues bearing mucin-type O-linked glycans. It has become an essential tool in glycoproteomic workflows, enabling site-specific analysis of O-glycosylation and facilitating the structural characterization of mucin-type glycopeptides
Product Description
IMPa (Immunomodulating Metalloprotease A) functions as a broad-specificity O-glycoprotease that specifically cleaves N-terminal to serine or threonine residues bearing mucin-type O-linked glycans, such as GalNAc (Tn), core 1 (T antigen), and their extended, branched, and sialylated derivatives. The enzyme’s activity is glycan-dependent, meaning it requires the presence of an O-GalNAc moiety at the cleavage site for recognition and catalysis, while the underlying peptide sequence plays a secondary role. IMPa exhibits high tolerance toward different sequences, making it broadly applicable across diverse glycoproteins. However, IMPa’s shows complete loss of activity when an aspartic acid (Asp, D) residue occupies the P1 position (immediately N-terminal to the glycosylated Ser/Thr. This defined yet flexible specificity allows IMPa to selectively target O-glycosylated regions for site-resolved glycoproteomic analysis while maintaining precision in cleavage mapping.
Additonal Information
| Synonyms | IMPa |
|---|---|
| Source (Organism/Expression) | Pseudomonas aeruginosa expressed in E. coli |
| Accession Number / UniProt | Accession Number / UniProt |
| Molecular Weight | 95.8 kDa (appears 100–130 kDa on SDS-PAGE) |
| Isoform / Subunit Structure | Amino acids 43–923 with C-terminal 6×His tag |
| Storage Buffer | 20 mM Tris-HCl, 100 mM NaCl, pH 7.5 |
| Concentration | 20 U/μL* |
| Storage Conditions | −80 °C |
| Recommended Applications | Proteomics and glycopeptide structural analysis |
| Catalogue Number | – |
| Purity | >95% by SDS-PAGE (see Figure 1) |
| Enzyme Activity Definition | One unit of IMPa is defined as the amount of enzyme required to cleave 300 pmol of GFP-tagged MUC1 glycopeptide in a total reaction volume of 20 μL (substrate concentration 15 μM) after incubation for 2 hours at 37 °C. Activity is visualized by SDS-PAGE as the complete cleavage of GFP from the peptide substrate (see Figure 2). |
