title: Novel dipeptidyl peptidase-4-inhibiting peptide derived from β-lactoglobulin.
abstract: Trypsin-treated β-lactoglobulin significantly decreased the glucose level after an oral glucose tolerance test using mice. We performed the present study to identify the active peptide inhibiting dipeptidyl peptidase-4 from trypsin-treated β-lactoglobulin. Trypsin-treated β-lactoglobulin showed a concentration-dependent inhibition for dipeptidyl peptidase-4, with an IC(50) value of 210 µM, although non-treated β-lactoglobulin showed no significant effect in the in vitro assay. The active peptide was isolated from trypsin-treated β-lactoglobulin and identified as the hexapeptide Val-Ala-Gly-Thr-Trp-Tyr (β-lactoglobulin f15-20). This hexapeptide also exhibited a concentration-dependent inhibitory effect and IC(50) value was 174 µM, suggesting that this hexapeptide is almost totally responsible for the DPP-4 inhibitory activity of trypsin-treated β-lactoglobulin.
authors.affiliation: Food Science Institute, Division of Research and Development, Meiji Corporation, Ltd., Japan. masayuki.uchida@meiji.com
authors.forename: Masayuki
authors.initials: M
authors.lastname: Uchida
authors.forename: Yukio
authors.initials: Y
authors.lastname: Ohshiba
authors.forename: Orie
authors.initials: O
authors.lastname: Mogami
mesh_terms: D018819:Dipeptidyl Peptidase 4 / Q000187:drug effects*; D007782:Lactoglobulins / Q000737:chemistry / Q000494:pharmacology*; D011480:Protease Inhibitors / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D007782:Lactoglobulins; D011480:Protease Inhibitors; D018819:Dipeptidyl Peptidase 4