Table 1. Dibasic Residue Cleavages of Peptide Substrates by Cathepsin L and Cathepsin V Cysteine Proteases and PC1/3 and PC2 Serine Proteasesa.
| protease | peptide | fold change (60 min) |
|---|---|---|
| cathepsin L | GnYYK↓RFnAHWVGI | 142 |
| TPHHVNWYK↓RAPNQ | 46 | |
| EGADIWYR↓KHSHQL | 5 | |
| TPHHVNWY↓KRAPNQ | 5 | |
| LGWHAnF↓RKYPInA | 124 | |
| cathepsin V | GnYYK↓RFnAHWVGI | 14 |
| TPHHVNWYK↓RAPNQ | 6 | |
| LGWHAnFR↓KYPInA | 12 | |
| DAWAPnVIK↓KESSI | 32 | |
| PC1/3 | GnYYKR↓FnAHWVGI | 395 |
| IEPPWVDSHAKR↓Nn | 23 | |
| VDYIEHKDQVRR↓nN | 14 | |
| PC2 | YWnSTHLAGKR↓RDW | 34 |
a
Dibasic peptide cleavage sites of peptide substrates are illustrated for cathepsin L, cathepsin V, PC1/3, and PC2. Cleavage sites were determined by the identification and quantification of cleaved peptide products. Cleaved peptide products analyzed were the NH2-terminal peptide fragments, except for EGADIWR↓KHSHQL, where its COOH-terminal peptide product was identified and quantified. The fold changes of the cleaved peptide product generated at 60 min compared to 0 min controls are shown. The non-natural amino acid norleucine is indicated as lowercase “n.”