Sensitivity of beta-casein phosphopeptide-iron complex to digestive enzymes in ligated segment of rat duodenum.
Binding iron to the phosphorylated beta(1-25) peptide derived from beta-casein improves iron bioavailability in the rat. The aim of the present work was to learn how injected beta(1-25) and iron-beta(1-25) complex behave in the duodenum of rats using the technique of intestinal ligation in situ and reversed-phase (RP)-high performance liquid chromatography-electrospray mass spectrometry analysis of the lumen contents. The results demonstrate that beta(1-25) is sensitive to digestive enzymes including proteases/peptidases and phosphatases during duodenal transit. The lumen contents of rats perfused with iron free beta(1-25) contained all peptidic sequences derived from beta(1-25). In contrast, the phosphorylated part of beta(1-25) [i.e., beta(15-24)] was not detected in lumen of rats perfused with iron-beta(1-25) complex.
Bouhallab
S
S
Laboratoire de Recherches de Technologie Laitière, INRA, Rennes, France.
Oukhatar
N A
NA
Mollé
D
D
Henry
G
G
Maubois
J L
JL
Arhan
P
P
Bouglé
D L
DL