Tyvelose is an unusual 3,6-dideoxyhexose terminal sugar and the immunodominant component of glycoprotein antigens in the parasitic helminth T. spiralis, which is responsible for trichinosis in humans. It is produced in high amounts by the infective larva and is immunodominant during the muscle stage of infection. Mice immunized with tyvelose-BSA produce IgG1 antibodies to tyvelose but are not resistant to infection by T. spiralis. Tyvelose-specific antibodies (2.5 mg 20 g) administered to rat pups leads to expulsion of first stage larvae from the intestine within one hour.
CCK (26-30) is an N-terminal fragment of CCK , a peptide hormone found in the intestine and brain that stimulates digestion, mediates satiety, and is involved in anxiety. The sulfated form of CCK (26-30) inhibits binding of [125I]CCK-33 to guinea pig cortical membranes by 10% when used at a concentration of 0.1 mM.
Enteropeptidase fluorogenic substrate is a substrate for enteropeptidase that contains a 7-amino-4-trifluoromethylcoumarin (AFC) moiety. Enteropeptidase is a serine protease expressed in the proximal small intestine of higher animals that converts inactive trypsinogen to active trypsin by endoproteolytic cleavage. Enteropeptidase recognizes the highly specific amino acid sequence DDDDK on the fluorogenic substrate and cleaves after the lysine residue, releasing the AFC moiety. Enteropeptidase activity is quantified by fluorescent detection of AFC, which displays excitation emission spectra of 380 500 nm.
CCK (26-31) is an N-terminal fragment of CCK , a peptide hormone found in the intestine and brain that stimulates digestion, mediates satiety, and is involved in anxiety.