Table 2.
Diagnostic b/y MS/MS fingerprint ions indicative of (A) all cyclotides, (B) bracelets, (C) Möbius, and (D) notable and often highly abundant bracelet ions that provide valuable information towards the identification of a mass species.
| (A) | All cyclotides | (B) | Bracelets | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| m/z | b/y | Seq | % Brac | % Möb | Brac ID | Möb ID | m/z | b/y | Seq | % Brac | % Möb | Brac ID | Möb ID |
| 148.06 | y | E | 100 | 100 | 70 | 30 | 248.07 | b | SC | 77 | 12 | 93 | 7 |
| 205.08 | y | EG | 84 | 98 | 66 | 34 | 347.14 | b | SCV | 70 | 2 | 99 | 1 |
| 365.11 | y | EGC | 83 | 97 | 66 | 34 | 462.17 | y | EGCP | 61 | 2 | 99 | 1 |
| (C) | Mobius | (D) | Informative Bracelet Peaks | ||||||||||
| m/z | b/y | Seq | % Brac | % Möb | Brac ID | Möb ID | m/z | b/y | Seq | % Brac | % Möb | Brac ID | Möb ID |
| 102.05 | b | T | 18 | 85 | 33 | 67 | 494.20 | b | SCVF | 27 | 0 | 100 | 0 |
| 262.09 | b | TC | 18 | 85 | 33 | 67 | 510.20 | b | SCVY† | 20 | 9 | 85 | 15 |
| 409.15 | b | TCF | 4 | 42 | 18 | 82 | 533.21 | b | SCVW | 24 | 0 | 100 | 0 |
| 464.18 | y | EGCV | 1 | 37 | 6 | 94 | 565.21 | b | SCVW(diOX)* | - | - | - | - |
| 561.23 | y | EGCVP | 5 | 37 | 25 | 75 | 590.23 | b | SCVW(Alk)* | - | - | - | - |
m/z species generated from common, often unintentional, modifications (di-oxidation, alkylation) of the aromatic bracelet peak; values for percent bracelet, percent Möbius, bracelet identification, and Möbius identification are not applicable.
All %Bracelet and Bracelet ID values derived from the shown sequence; however, %Möbius and Möbius ID values were calculated from a same mass (510.20 m/z) but different sequence: the bracelet and Möbius values here are not derived from the same amino acid sequence, but both produce the 510.20 m/z ion, necessitating that the 510.20 m/z value be assigned to a bracelet ‘SCVY’ motif only when observed in combination with 248.07 and 347.14 m/z b-ions.