A sensitive and specific enzyme immunoassay for vasoactive intestinal polypeptide (VIP)-like immunoreactivity was developed with the use of synthetic carboxy-terminal (C-terminal) fragment (residue 11—28) of porcine VIP conjugated with β-D-galactosidase and a second antibody-coated immunoplate. Using 4-methylumbelliferyl β-D-galactopyranoside as a fluorogenic substrate, the minimum amount of VIP-like immunoreactive substance (VIP-IS) detectable by this method was O.l fmol/well (2.5 pmol/l). The level of VIP-IS in bovine foremilk was above 100pmol/l, which was more than eightfold higher than that in normal milk.
- 4-methylumbelliferyl β-D-galactopyranoside
- highly sensitive enzyme immunoassay VIP(11—28)-linked β-D- bovine foremilk
- vasoactive intestinal polypeptide (VIP)-like immunoreactive substance
ASJC Scopus subject areas
- Drug Discovery