Susceptibility to transglutaminase of gliadin peptides predicted by a mass spectrometry-based assay.
A peptidomics approach was developed to identify transglutaminase-susceptible Q residues within a pepsin-trypsin gliadin digest. Based on tagging with a monodansylcadaverine fluorescent probe, six alpha/beta-, gamma-gliadin, and low molecular weight glutenin peptides were identified by nanospray tandem mass spectrometry. In functioning as an acyl acceptor, tissue transglutaminase was able to form complexes with the glutamine-rich gliadin peptides, whereas by lowering pH, the peptides were deamidated by transglutaminase at the same Q residues, which were previously transamidated. The main common feature shared by the peptides was the consensus sequence Q-X-P. Our findings offer relevant information for the understanding of how dietary peptides interact with the host organism in celiac disease.
Mamone
Gianfranco
G
Istituto di Scienze dell'Alimentazione del CNR, Avellino, Italy. mamone@isa.av.cnr.it
Ferranti
Pasquale
P
Melck
Dominique
D
Tafuro
Filomena
F
Longobardo
Luigi
L
Chianese
Lina
L
Addeo
Francesco
F
D000595:Amino Acid Sequence; D000818:Animals; D001323:Autoantibodies / Q000276:immunology; D005903:Gliadin / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D006168:Guinea Pigs; D006801:Humans; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011503:Transglutaminases / Q000378:metabolism*
D001323:Autoantibodies; D010455:Peptides; D005903:Gliadin; D011503:Transglutaminases