Table 1. Structures of the Modified Tobramycin and Peptides Used in This Work as Well as Their Conjugates, with Calculated and Measured Molecular Masses.
| Name | Sequence | Mcalcc | Mfoundd |
|---|---|---|---|
| mTob-Cys-NH2 | Tobramycin(hemisuccinate)-Cys-NH2 | 670.2 | 670.5 |
| Bac7(1–15)[Cys16]-NH2 | H-RRIRPRPPRLPRPRPC-NH2 | 2022.5 | 2022.3 |
| aBac7(1–15)[Cys16ALK]-NH2 | H-RRIRPRPPRLPRPRPC(Alk)-NH2 | 2079.3 | 2079.5 |
| mTob-Bac7(1–15)[Cys16]-NH2 | mTob-⌜C-NH2 H-RRIRPRPPRLPRPRP⌝C-NH2 | 2690.0 | 2689.9 |
| Bac7(1–35)[Cys36]-OH | H-RRIRPRPPRLPRPRPRPLPFPRPGPRPIPRPLPFPC-OH | 4310.3 | 4310.8 |
| bBac7(1–35)[Cys36ALK]-OH | H-RRIRPRPPRLPRPRPRPLPFPRPGPRPIPRPLPFPC(Alk)-OH | 4368.3 | 4368.0 |
| mTob-Bac7(1–35)[Cys36]-OH | mTob-⌜C-NH2 H-RRIRPRPPRLPRPRPRPLPFPRPGPRPIPRPLPFP⌝C-OH | 4978.7 | 4978.5 |
a
ALK indicates an acetylated C-terminal Cys thiol, which is also amidated.
b
The C-terminal Cys residue is side-chain acetylated but not amidated.
c
Calculated using Peptide Mass Calculator (PeptideWeb.com) as the average mass.
d
Measured by ESI-MS in positive mode.