Table 5 Fragment b- and y-ions attributed to the tryptic peptide SHnIALIWnVKDFmSLSEQLR as identified by tandem MS. The table also includes complementary fragment ions that aided in the assignment of the peptide
From: Identification of SARS-CoV-2 biomarkers in saliva by transcriptomic and proteomics analysis
| Â | Calculated mass | Measured mass | Fragment b-ions | Calculated mass | Measured mass |
|---|---|---|---|---|---|
Fragment y-ions | Â | Â | Â | ||
y1+ | 175.1190 | ND | b1+ | 88.0393 | 88.0398 |
y2+ | 288.1554 | ND | b2+ | 225.0982 | ND |
y3+ | 416.2616 | ND | b3+ | 340.1252 | 340.1251 |
y4+ | 545.3042 | ND | b4+ | 453.2092 | 453.2190 |
y5+ | 632.3362 | 632.3167 | b5+ | 524.2463 | ND |
y6+ | 745.4203 | 745.3849 | b6+ | 637.3304 | ND |
y7+ | 832.4523 | 832.4116 | b7+ | 750.4145 | 750.4075 |
y8+ | 979.4877 | 979.4992 | b8+ | 936.4938 | 936.4562 |
y9+ | 1126.5561 | 1126.5710 | b9+ | 1051.5207 | 1051.5223 |
y10+ | 1241.5831 | ND | b10+ | 1150.5891 | ND |
y11+ | 1369.678 | ND | b11+ | 1278.6841 | 1278.6585 |
y12+ | 1468.7464 | 1468.7364 | b12+ | 1393.711 | 1393.7281 |
y13+ | 1583.7734 | ND | b13+ | 1540.7795 | 1540.7964 |
Complementary ions | |||||
LS-H2O | 183.1128 | 183.1166 | b11+2 | 639.8457 | 639.8275 |
nI | 229.1183 | 229.1239 | b12+2 | 697.3592 | 697.3686 |
y12+2 | 490.2537 | 490.2538 | y9+-NH3 | 1109.5296 | 1109.5421 |
y9+-NH3 | 555.2684 | 555.2804 | LIWnVKDFm-NH3 | 1147.5492 | 1147.6083 |
y8+-NH3 | 962.4612 | 962.4727 | KDFmSLSEQL-28 | 1167.5714 | 1167.6321 |
y11+-NH3 | 1352.6515 | 1352.6648 | WnVKDFmS-28 | 997.4448 | 997.5106 |
EQ-28 | 230.1245 | 230.1247 | VKDFmSLSEQL-H2O | 1276.6242 | 1276.6532 |
EQ-NH3 | 241.0819 | 241.0861 | VKDF-NH3 | 473.2395 | 473.2306 |
(y8-NH3)+2 | 481.7342 | 481.7397 | KD | 244.1292 | 244.1135 |