Monitoring of in vitro deamidation of gliadin peptic fragment by mass spectrometry may reflect one of the molecular mechanisms taking place in celiac disease development.
Celiac disease, a chronic disorder of the small intestine, is caused by dietary gluten and is characterized by villous atrophy and local inflammation associated with infiltration of B and T lymphocytes and/or macrophages into the intestinal wall. In genetically predisposed individuals, the infiltrating cells are activated by gluten, gliadin and their proteolytic fragments and produce chemokines, cytokines and reactive radicals. The sequence of one of the macrophage-stimulatory gliadin peptic fragment was determined by mass spectrometry (MS) as VSFQQPQQQYPSSQ. The role of tissue transglutaminase (tTG) in innate immunity stimulation was studied by mass spectrometric monitoring of sequence changes in this active peptide. Two sites of glutamine deamidation in this peptide were localized by high-resolution scanning in MS/MS mode in an ion trap. A single deamidation in the parent peptide led to the complete loss of its stimulatory effect on macrophages.
Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídenská 1083, CZ-142 20 Prague 4, Czech Republic.
Petr
P
Novák
Petr
P
Man
Ludmila
L
Tucková
Helena
H
Tlaskalová-Hogenová
Karel
K
Bezouska
Vladimír
V
Havlícek
D000595:Amino Acid Sequence; D000818:Animals; D002446:Celiac Disease / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism; D005903:Gliadin / Q000032:analysis* / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D006168:Guinea Pigs; D006801:Humans; D016753:Interleukin-10 / Q000378:metabolism; D008262:Macrophage Activation / Q000187:drug effects; D008969:Molecular Sequence Data; D009569:Nitric Oxide / Q000378:metabolism; D009842:Oligopeptides / Q000032:analysis* / Q000494:pharmacology; D010446:Peptide Fragments / Q000032:analysis* / Q000494:pharmacology; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011499:Protein Processing, Post-Translational; D020539:Sequence Analysis, Protein; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D011503:Transglutaminases / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D009842:Oligopeptides; D010446:Peptide Fragments; D014409:Tumor Necrosis Factor-alpha; C463320:VSFQQPQQQYPSSQ; D005973:Glutamine; D016753:Interleukin-10; D009569:Nitric Oxide; D018698:Glutamic Acid; D005903:Gliadin; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D019204:GTP-Binding Proteins