Table 1. Peptides and derivatives used in the present study.
The molar absorption coefficients are for 268 nm unless otherwise indicated. Calculated molecular masses are given; values determined experimentally by MS were within 0.05% of the calculated mass. The Trimeresurus wagleri venom peptide II (Twvp), a likely competitive antagonist of nicotinic acetylcholine receptors [51], was used as a control. OG, Oregon Green.
| Peptide | Sequence | Molecular mass (Da) | Molar absorption coefficient (M−1·cm−1) |
|---|---|---|---|
| Tat | YGRKKRRQRRRP | 1657.0 | 1304 |
| TPP4Tat | TPP-C4-YGRKKRRQRRRP | 1988.3 | 4669 |
| TPP8Tat | TPP-C8-YGRKKRRQRRRP | 2044.5 | 4669 |
| TPP12Tat | TPP-C12-YGRKKRRQRRRP | 2100.6 | 4669 |
| Tat-Cys | YGRKKRRQRRRPC | 1760.1 | 1304 |
| TPP4Tat-Cys | TPP-C4-YGRKKRRQRRRPC | 2147.6 | 4669 |
| Tat-Cys–OG | YGRKKRRQRRRPC–OG | 2223.5 | ∼81000 (491 nm) |
| TPP4Tat-Cys–OG | TPP-C4-YGRKKRRQRRRPC–OG | 2610.9 | ∼81000 (491 nm) |
| Cys-Tat | CYGRKKRRQRRRP | 1760.1 | 1304 |
| Pen | RQIKIWFQNRRMKWKK | 2246.8 | 9665 |
| TPP4Pen | TPP-C4-RQIKIWFQNRRMKWKK | 2578.2 | 13030 |
| TPP8Pen | TPP-C8-RQIKIWFQNRRMKWKK | 2634.3 | 13030 |
| TPP12Pen | TPP-C12-RQIKIWFQNRRMKWKK | 2690.4 | 13030 |
| Cys-Pen | CRQIKIWFQNRRMKWKK | 2349.9 | 9665 |
| Twvp | GGKPDLRPCYPPCHYIPRPKPR | 2546.0 | 3040 (280 nm) |