Table 1. Sequences of detected peptides and their Mascot E-values.
| Mascot E-value | |||||
|---|---|---|---|---|---|
| Peptide name |
ID |
Peptide sequence | Peptide database Cnidarian-specific motifs |
Protein database No motif |
Peptide database- bilaterian neuropeptide processing motif |
| HIRamide | 1 | APPLDLSGPAYFHIRa | 1.9E-02 | 4.2E+00 | nd |
| 2 | GPPYIDLTEPSFFHIRa | 8.8E-09 | 2.1E-06 | nd | |
| 3 | NPPIDLGPAYFHIRa | 7.3E-07 | 1.6E-04 | 5.9E-07 | |
| 4 | pQPPIDLSPAAYFHIRa | 1.1E-04 | 2.5E-02 | 7.7E-05 | |
| 5 | pQPPLDLGPAYFHIRa | 5.0E-07 | 1.1E-04 | nd | |
| 6 | pQPPYLDLGEPSFFHIRa | 4.5E-04 | 1.0E-01 | 3.6E-04 | |
| 7 | pQPPYLDLTPAYFHIRa | 2.5E-04 | 5.5E-02 | nd | |
| 8 | pQPPYLDLTPSYFHIRa | 5.4E-06 | 1.2E-03 | nd | |
| 9 | pQPPMIDLSEPAFFHIRa | 1.2E-06 | 2.7E-04 | nd | |
| 10 | pQQPPMIDLSEPAFFHIRa | 1.7E-03 | 3.5E-01 | nd | |
| PRGamide | 11 | GPRGGRATEFGPRGa | 1.2E-04 | 2.8E-02 | nd |
| 12 | GPRGGREVNLEGPRGa | 6.7E-03 | 1.7E+00 | nd | |
| QWamide | 13 | IPPQGFRFNQWa | 3.4E-02 | 8.2E+00 | nd |
| 14 | IPPQGLRFNQWa | 2.9E-03 | 6.7E-01 | nd | |
| 15 | IPPQGLRFSQWa | 2.8E-03 | 6.4E-01 | nd | |
| RFamide | 16 | MPEQDANPQTRFDa | 2.3E-05 | 5.3E-03 | nd |
| 17 | pQGRFGREDQGRFa | 3.2E-03 | 6.3E-01 | nd | |
| RPamide | 18 | FPPGFHRPa | 2.0E-03 | 4.9E-01 | nd |
| RHamide | 19 | GPPMIKIPVRHa | 2.0E-03 | 5.0E-01 | nd |
| 20 | GPPMoIKIPVRHa | 7.7E-04 | 2.5E+01 | nd |
E-values lower than the threshold (0.05) are indicated in bold. Mascot E-values in the first column result from peptide spectrum matching (PSM) against the smaller dataset of peptides extracted in silico. Mascot E-values in the second column result from PSM against the Nematostella protein database. Mascot e-values in the third column result from PSM against a database of peptide sequences that were extracted from the Nematostella protein database using the most common neuropeptide processing motif, which is based on the presence of dibasic cleavage sites as substrates for prohormone convertases and carboxypeptidase E in bilaterian neuropeptide precursors. C-terminal amidation, oxidation, and N-terminal pyroglutamic acid are indicated as “a”, “o,” and “p,” respectively. PC: protein convertase; nd: not detected.