Figure 1.
Derivatization of peptides with AccQ and generation of AccQ-derived product ions (b1, m/z = 171.1) via tandem mass spectrometry.
| Journal of Food Bioactives, ISSN 2637-8752 print, 2637-8779 online |
| Journal website www.isnff-jfb.com |
Original Article
Volume 2, Number , June 2018, pages 104-111
Identification of food-derived peptides in human blood after ingestion of corn and wheat gluten hydrolysates
Figures
Derivatization of peptides with AccQ and generation of AccQ-derived product ions (b1, m/z = 171.1) via tandem mass spectrometry.
Mass spectrometry chromatograms of AccQ-derivatives (a, b) and pyroglutamyl peptides (c) in SEC fractions 35-40. Peaks marked with uppercase represent amino acid derivatives; lowercase, AccQ-peptides (a-j) and pyroglutamyl peptides (k-t). Peaks marked with asterisks could not be assigned to peptides with any combination of amino acids.
Contents of exopeptidase-resistant peptides from corn and wheat gluten hydrolysates.
One-letter abbreviations were used for amino acid residues. pE represents pyroglutamic acid (pyroGlu) residue.
Contents of the exopeptidase-resistant peptides in human blood plasma after ingestion of corn or wheat gluten hydrolysates.
Data are shown as the mean ± standard deviation (n = 4). Asterisks indicate significant differences between values before ingestion (*: P < 0.05, **: P < 0.01, ***: P < 0.001).Table
| Origin | SEC Fr. | peak | estimated peptide sequence | precursor ions (m/z) | product ions (m/z) |
|---|---|---|---|---|---|
| *Immonium ion of amino acid. ** Peaks a-j were AccQ derivatives. SEC: size-exclusion chromatography. | |||||
| C, W | 37, 38 | a | Gly-Pro | 343.3 | 116.1 (y1), 171.0 (AccQ, b1), 228 (b2) |
| C, W | 36–38 | b | Ser-Pro | 373.2 | 116.1 (y1), 171.0 (AccQ, b1), 203 ([y2-NH3]+), 258 (b2) |
| C, W | 36–38 | b | Asp-Pro | 401.2 | 70.1 (Asp*), 116 (y1), 171.0 (AccQ, b1), 231 ([y2-NH3]+), 258 (a2), 286 (b2) |
| C, W | 36–38 | b | Gln-Pro | 414.3 | 83.9 (Gln*), 101.1 (Gln*), 116.1 (y1), 171.0 (AccQ, b1), 271.1 (a2), 298.9 (b2) |
| C, W | 36–37 | c | Ala-Pro | 357.3 | 116.1 (y1), 171.0 (AccQ, b1), 187 ([y2-NH3]+), 242.1 (b2) |
| C, W | 36–37 | c | Pro-Pro | 383.3 | 70.1 (Pro*), 116.1 (y1), 171.0 (AccQ, b1), 213 ([y2-NH3]+), 268.1 (b2) |
| C, W | 36 | d | Pro-Val | 385.3 | 70.1 (Pro*), 171.0 (AccQ, b1), 215 ([y2-NH3]+) |
| C, W | 36–37 | e | Pro-Ile/Leu | 399.3 | 70.1 (Pro*), 171.0 (AccQ, b1), 229.1 ([y2-NH3]+), 240 (a2), 268.2 (b2) |
| C, W | 36–37 | f | Val-Pro | 385.3 | 72.1 (Val*), 116.1 (y1), 171.0 (AccQ, b1), 215 ([y2-NH3]+), 242 (a2), 270.2 (b2) |
| C, W | 36–37 | g | Ile-Pro | 399.3 | 86.1 (Ile*), 116.1 (y1), 171.0 (AccQ, b1), 229.1 ([y2-NH3]+), 256.1 (a2), 284.1 (b2) |
| C, W | 36–37 | h | Leu-Pro | 399.3 | 86 (Leu*), 116.1 (y1), 171.0 (AccQ, b1), 229.1 ([y2-NH3]+), 256.1 (a2), 284 (b2) |
| C, W | 37–38 | i | Asn-Pro | 400.3 | 70.1 (Asn*), 116 (y1), 171.0 (AccQ, b1), 230 ([y2-NH3]+), 256.9 (a2), 285 (b2) |
| C, W | 38–40 | j | Phe-Pro | 433.3 | 116 (y1), 120 (Phe*), 171.0 (AccQ, b1), 263 ([y2-NH3]+), 290.1 (a2), 318 (b2) |
| C, W | 35–36 | k | pyroGlu-Gln-Pro | 355.1 | 70.1 (Pro*), 84 (pyroGlu*), 116 (y1), 212 (a2), 240 (b2) |
| C, W | 35–37 | l | pyroGlu-Leu-Pro | 340.2 | 70.1 (Pro*), 84 (pyroGlu*), 86 (Leu*), 197.1 (a2) |
| C, W | 36–38 | m | pyroGlu-Gln | 258.1 | 84 (pyroGlu*) |
| C, W | 37–38 | n | pyroGlu-Ala | 201.1 | 44.1 (Ala*), 84 (pyroGlu*), 89.9 (y1) |
| C, W | 37 | o | pyroGlu-Pro | 227 | 70.1 (Pro*), 83.9 (pyroGlu*), 115.9 (y1) |
| C, W | 37–38 | p | pyroGlu-Val | 229.1 | 72.1 (Val*), 84 (pyroGlu*), 118.1 (y1) |
| C, W | 38–39 | q | pyroGlu-Ile | 243.1 | 86.0 (Ile*), 84 (pyroGlu*) |
| C, W | 38–39 | r | pyroGlu-Leu | 243.1 | 86.0 (Leu*), 84 (pyroGlu*), 132.2 (y1) |
| C, W | 39–40 | s | pGlu-Glu | 259 | 84 (pyroGlu*) |
| W | 39–40 | t | pyroGlu-Phe-Pro | 374.1 | 70.1 (Pro*), 84 (pyroGlu*), 116 (y1), 120 (Phe*), 231 (a2) |