Dimeric inhibitors of human salivary alpha-amylase from emmer (Triticum dicoccon Schrank) seeds.
The proteins belonging to the cereal trypsin/alpha-amylase inhibitor family are abundant water/salt-soluble flour proteins active against alpha-amylases from several seed parasites and pests and inactive against endogenous alpha-amylases. Three alpha-amylase inhibitor families have been described in cereals that vary in size and are differently expressed among Triticeae seeds. The present work investigates the presence of human salivary alpha-amylase inhibitors in emmer (Triticum dicoccon Schrank) flour. The isolation was obtained by a series of chromatography steps, and the purification progress was monitored through the inhibition of human salivary alpha-amylase activity. The purified fraction was subjected to protein sequencing by tandem mass spectrometry (MSMS) of the tryptic digests obtained after the sample separation on 2-DE. MSMS data indicated that the emmer alpha-amylase inhibitory fraction was composed of two newly identified proteins [emmer dimeric inhibitor 1 (EDI-1) and emmer dimeric inhibitor 2 (EDI-2)] sharing very high identity levels with related proteins from Triticum aestivum.
Fontanini
Debora
D
Department of Biology, University of Pisa, Via L. Ghini 5, 56126 Pisa, Italy. dfontanini@biologia.unipi.it
Capocchi
Antonella
A
Muccilli
Vera
V
Saviozzi
Franco
F
Cunsolo
Vincenzo
V
Saletti
Rosaria
R
Foti
Salvatore
S
Galleschi
Luciano
L
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology; D019281:Dimerization; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis / Q000737:chemistry / Q000494:pharmacology; D012463:Saliva / Q000201:enzymology*; D012639:Seeds / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014908:Triticum / Q000737:chemistry*; D014357:Trypsin / Q000378:metabolism; D000516:alpha-Amylases / Q000037:antagonists & inhibitors*
D004791:Enzyme Inhibitors; D010446:Peptide Fragments; D000516:alpha-Amylases; D014357:Trypsin