Peptides surviving the simulated gastrointestinal digestion of milk proteins: biological and toxicological implications.
Resistance to proteases throughout the gastrointestinal (GI) tract is a prerequisite for milk-derived peptides to exert biological activities. In this work an in vitro multi-step static model to simulate complete digestion of the bovine milk proteins has been developed. The experimental set-up involved the sequential use of: (i) pepsin, (ii) pancreatic proteases, and (iii) extracts of human intestinal brush border membranes, in simulated gastric, duodenal and jejuneal environments, respectively. Enzymatic concentrations and reaction times were selected in order to closely reproduce the in vivo conditions. The aim was to identify the peptide candidates able to exhibit significant bioactive effects. Casein and whey protein peptides which survived the in vitro GI digestion have been identified by the combined application of HPLC and mass spectrometry techniques. While the permanence of the main potentially bioactive peptides from both casein and whey proteins was found of limited physiological relevance, the high resistance to proteolysis of specific regions of beta-lactoglobulin (beta-Lg), and especially that of the peptide beta-Lg f125-135, could have implications for the immunogenic action of beta-Lg in the insurgence of cow's milk allergy.
Picariello
Gianluca
G
Istituto di Scienze dell'Alimentazione-CNR, Via Roma 52 A/C, I-83100 Avellino, Italy. picariello@isa.cnr.it
Ferranti
Pasquale
P
Fierro
Olga
O
Mamone
Gianfranco
G
Caira
Simonetta
S
Di Luccia
Aldo
A
Monica
Stefano
S
Addeo
Francesco
F
D000595:Amino Acid Sequence; D000818:Animals; D002364:Caseins / Q000737:chemistry / Q000378:metabolism; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase; D004063:Digestion; D041981:Gastrointestinal Tract / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D007782:Lactoglobulins / Q000737:chemistry / Q000378:metabolism; D008894:Milk Proteins / Q000737:chemistry / Q000378:metabolism*; D008954:Models, Biological; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000633:toxicity*; D010748:Phosphopeptides / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D055550:Protein Stability; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D000067816:Whey Proteins
D002364:Caseins; D007782:Lactoglobulins; D008894:Milk Proteins; D010446:Peptide Fragments; D010455:Peptides; D010748:Phosphopeptides; D000067816:Whey Proteins