Mining and Validation of Novel Hemp Seed-Derived DPP-IV-Inhibiting Peptides Using a Combination of Multi-omics and Molecular Docking

Hemp
seed-derived inhibitors of dipeptidyl peptidase IV (DPP-IV)
demonstrate potential as novel therapeutics for diabetes; however,
their proteome and genome remain uncharacterized. We used multi-omics
technology to mine peptides capable of inhibiting DPP-IV. First, 1261
and 1184 proteins were identified in fresh and dry hemp seeds, respectively.
Simulated protease cleavage of dry seed proteins yielded 185,446 peptides
for virtual screening to select the potential DPP-IV-inhibiting peptides.
Sixteen novel peptides were selected according to their DPP-IV-binding
affinity determined via molecular docking. In vitro DPP-IV inhibition
assays identified the peptides LPQNIPPL, YPYY, YPW, LPYPY, WWW, YPY,
YPF, and WS with half-maximal inhibitory concentration (IC50) values lower than 0.5 mM, which were 0.08 ± 0.01, 0.18 ±
0.03, 0.18 ± 0.01, 0.20 ± 0.03, 0.22 ± 0.03, 0.29 ±
0.02, 0.42 ± 0.03, and 0.44 ± 0.09 mM, respectively. The
dissociation constants (KD) of the 16
peptides ranged from 1.50 × 10–4 to 1.82 ×
10–7 M. Furthermore, Caco2 and INS-1 cell assays
showed that all 16 peptides could efficiently inhibit DPP-IV activity
and increase insulin and glucagon-like peptide-1 concentrations. These
results demonstrate a well-established and efficient method to isolate
food-derived therapeutic DPP-IV-inhibiting peptides.