title: Identification of lanthionine and lysinoalanine in heat-treated wheat gliadin and bovine serum albumin using tandem mass spectrometry with higher-energy collisional dissociation.
abstract: 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.
authors.affiliation: Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20, Box 2463, 3001, Leuven, Belgium. ine.rombouts@biw.kuleuven.be.
authors.forename: Ine
authors.initials: I
authors.lastname: Rombouts
authors.affiliation: Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20, Box 2463, 3001, Leuven, Belgium.
authors.forename: Marlies A
authors.initials: MA
authors.lastname: Lambrecht
authors.affiliation: Laboratory for Tropical Crop Improvement, KU Leuven, Willem de Croylaan 42, Box 2455, 3001, Leuven, Belgium.|Facility for SYstems BIOlogy Based MAss Spectrometry, Herestraat 49, 3000, Leuven, Belgium.
authors.forename: Sebastien C
authors.initials: SC
authors.lastname: Carpentier
authors.affiliation: Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20, Box 2463, 3001, Leuven, Belgium.
authors.forename: Jan A
authors.initials: JA
authors.lastname: Delcour
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification; D000818:Animals; D002417:Cattle; D002918:Chymotrypsin / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry; D003553:Cystine / Q000737:chemistry; D005903:Gliadin / Q000737:chemistry*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008239:Lysine / Q000737:chemistry; D008241:Lysinoalanine / Q000737:chemistry / Q000302:isolation & purification*; D059748:Proteolysis; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013440:Sulfides / Q000737:chemistry / Q000302:isolation & purification*; D013912:Threonine / Q000737:chemistry; D014908:Triticum / Q000737:chemistry; D014357:Trypsin / Q000737:chemistry
chemical_list: D013440:Sulfides; D008241:Lysinoalanine; D012710:Serum Albumin, Bovine; D013912:Threonine; D003553:Cystine; D005903:Gliadin; C015102:dehydroalanine; D002918:Chymotrypsin; D014357:Trypsin; C001520:lanthionine; D008239:Lysine; D003545:Cysteine; D000409:Alanine
keywords: Higher-energy collisional dissociation; LC–ESI–MS/MS; Michael addition; Orbitrap; Protein cross-links; β-Elimination