Table 2.
Peptide name | [M + H]+ m/z (theoretical)a | [M + H]+ m/z (experimental) | Amino acid sequenceb | Position |
---|---|---|---|---|
β1 | 2061.83 | 2062 | FQ[pS]EEQQQTEDELQDK | 48–63 |
β2 | 2556.09 | 2557 | FQ[pS]EEQQQTEDELQDKIHPF | 48–67 |
β3 | 3122.26 | 3122 | RELEELNVPGEIVE[pS]L[pS][pS][pS]EESITR | 16–40 |
Theoretical masses determined with the PeptideMass tool in ExPASy (Expert Protein Analysis System, http://www.uniprot.org) using UniProtKB data for β-casein (entry ID: P02666).
[pS] represents a phosphorylated serine residue, and is included in the theoretical mass calculation.