Table 1. Fragment ions from various peptides upon dissociation within the SCGD. Only fragments with m/z ≥ 150 are included. Sequence coverage of the SCGD, compared to ESI-MS with CID, is also shown.
| Name, # residues | Peptide sequence | an | bn | cn | xn | yn | dn | Internal fragments | Identified residues |
|
| SCGD | ESI-MS/MS | |||||||||
| Renin substrate I, 8 | Suc-RPFHLLVY-AMC | — | 2–8 | — | — | 1–8 | a5, a7 | — | 8/8, 100% | 4/8, 50% |
| Angiotensin I, 10 | DRVYIHPFHL | — | 4, 7–10 | — | 5, 8 | 2–10 | a6, b6 | — | 10/10, 100% | 3/10, 30% |
| Angiotensin II, 8 | DRVYIHPF | 6 | 5–8 | — | 4 | 3–8 | — | — | 8/8, 100% | 2/8, 25% |
| Bradykinin, 9 | RPPGFSPFR | 5 | 5, 7–9 | 4, 5 | — | 2–9 | a6, a9 | — | 9/9, 100% | 3/9, 33% |
| Substance P, 11 | RPKPQQFFGLM | 5, 7, 8, 10 | 3–11 | 4–10 | — | 8–11 | a6, a11 | — | 11/11, 100% | 6/11, 55% |
| SAMS peptide, 15 | Biotin-HMRSAMpSGLHLVKRR | 1, 2 | 1–3 | 1–6 | — | — | — | GLHLV+, [SGLHLVKR]+–NH3 | 6/15, 40% | 9/15, 60% a |
| [d-Ala2,d-Leu5]-enkephalin, 5 | YADGFLD | 4–5 | 3–5 | — | — | 2–5 | — | — | 5/5, 100% b | 5/5, 100% |
| Met-enkephalin, 5 | YGGFL | — | — | — | — | — | — | [M – CH3SH]H+ | 0/5, 0% | 5/5, 100% |
aSequence coverage achieved only through MS3 as MS/MS produced exclusively [M – H3PO4 + H3]3+.
bDetected fragment ions were all less than 1% abundance relative to the protonated molecular ion of the peptide.