Identification of lanthionine and lysinoalanine in heat-treated wheat gliadin and bovine serum albumin using tandem mass spectrometry with higher-energy collisional dissociation.
The present manuscript reports on the identification of various dehydroamino acid-derived bonds and cross-links resulting from thermal treatment (excess water, 240 min, 130 °C) of two model food proteins, bovine serum albumin, and wheat gliadin. S-Carbamidomethylated tryptic and chymotryptic digests of unheated (control) and heated serum albumin and gliadin, respectively, were analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-ESI-MS/MS) with higher-energy collisional dissociation (HCD). Heat-induced β-elimination of cystine, serine and threonine, and subsequent Michael addition of cysteine and lysine to dehydroalanine and 3-methyl-dehydroalanine were demonstrated. Lanthionine, lysinoalanine, 3-methyl-lanthionine, and 3-methyl-lysinoalanine were identified. The detection of inter-chain lanthionine in both bovine serum albumin and wheat gliadin suggests the significance of these cross-links for food texture.
['Rombouts|Ine|I|', 'Lambrecht|Marlies A|MA|', 'Carpentier|Sebastien C|SC|', 'Delcour|Jan A|JA|']
D000409:Alanine D000818:Animals D002417:Cattle D002918:Chymotrypsin D003545:Cysteine D003553:Cystine D005903:Gliadin D006358:Hot Temperature D006863:Hydrogen-Ion Concentration D008239:Lysine D008241:Lysinoalanine D059748:Proteolysis D012710:Serum Albumin, Bovine D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization D013440:Sulfides D013912:Threonine D014908:Triticum D014357:Trypsin
Higher-energy collisional dissociation β-Elimination Michael addition LC–ESI–MS/MS Orbitrap Protein cross-links