open access

https://hdl.handle.net/2115/15861

Characterization of Binding Between the Rat Small Intestinal Brush-border Membrane and Dietary Proteins in the Sensory Mechanism of Luminal Dietary Proteins.

英語

binding

2001-05

Japan Society for Bioscience, Biotechnology, and Agrochemistry

Bioscience Biotechnology and Biochemistry

65(5)

1007-1015

Dietary proteins are recognized by the gastrointestinal tract to display physiological functions, however, the sensory mechanism of the intestinal mucosa is not known. We examined binding properties between the rat small intestinal brush-border membrane (BBM) and proteins by using a surface plasmon resonance biosensor. BBM and solubilized BBM prepared from the rat jejunum bound to casein immobilized on the sensor surface, but not to bovine serum albumin. The ileal BBM showed less binding to casein than the jejunal BBM. Solubilized BBM binding to immobilized α-casein was slightly inhibited by aminopeptidase inhibitors, but still more inhibited by addition of casein with the inhibitors. Guanidinated casein inhibited the solubilized BBM binding to α-casein more strongly than casein (casein sodium and α-casein) inhibited. Trypsinization of solubilized BBM abolished its binding activity to α-casein. These results indicate that some membrane protein, but not aminopeptidases, contained in BBM interacts with dietary proteins, and that guanidinated casein has a higher affinity for BBM than intact casein. These binding intensities for proteins were closely correlated to physiological responsiveness, and are possibly involved in a sensory system for dietary protein in the intestine.

学術雑誌論文

Version of Record

0916-8451

1347-6947