Table 2.
Peptide and Segment Informationa
| name | sequenceb | M. W. (g/mol) | enzyme | description |
|---|---|---|---|---|
| EF | SGFRGGRGG-Am | 848.43 | N/A | two Arg, +2 charge |
| TF | SGFACGAGC-Am | 770.28 | N/A | two Cys, dithiol bridge |
| AF | SGFFPC-Am | 655.28 | N/A | two Phe, aromatic moiety |
| Mega | DDDTSAVLQ↓SGFFRCRPC-Am | 2014.90 | Mpro | Zwitterionic, dithiolate, and aromatic substrate |
a
The electrostatic fragment (EF), thiolate fragment (TF), and aromatic fragment (AF) could induce aggregation of the AuNPs via electrostatic, covalent, and π–π interactions, respectively. The Mega peptide after proteolysis can trigger AuNP aggregation via these multiple interactions.
b
All peptides have a free N-terminus (i.e., uncharged −NH2 at pH 8.0) and an amidated C-terminus (i.e., -Am). ↓ designates the Mpro cleavage site.