Release of dipeptidyl peptidase IV (DPP-IV) inhibitory peptides from milk protein isolate (MPI) during enzymatic hydrolysis
Related Experiment Video
Updated: Mar 6, 2026
A RAPID Method for Blood Processing to Increase the Yield of Plasma Peptide Levels in Human Blood
Published on: April 28, 2016
Alice B Nongonierma1, Caterina Mazzocchi2, Sara Paolella1
1Department of Biological Sciences, University of Limerick, Limerick, Ireland; Food for Health Ireland (FHI), University of Limerick, Limerick, Ireland.
Abstract:
The release of dipeptidyl peptidase IV (DPP-IV) inhibitory peptides from bovine milk protein isolate (MPI) during trypsin hydrolysis was studied using a design of experiments (DOE) approach. A 3 factor×3 level DOE including temperature (40, 50 and 60°C), enzyme to substrate ratio (E:S; 0.50, 1.25 and 2.00% (w/w)) and hydrolysis time (60, 150 and 240min) was used during the generation of 15 hydrolysates (H1-H15). The degree of hydrolysis (DH) varied between 6.98±0.31 (H8) to 12.75±0.62% (H10). The DPP-IV half maximal inhibitory concentration (IC50) ranged from 0.68±0.06 (H11)/0.68±0.10 (H4) to 1.59±0.11mgmL-1 (H8). Temperature had no effect (p>0.05) on the DPP-IV IC50 value, while an increase in E:S or time significantly decreased DPP-IV IC50 value (p<0.05). The DPP-IV IC50 value of 0.69mgmL-1, predicted by response surface methodology (RSM), to be obtained with an hydrolysate generated at 50.5°C, 2% ES and 231min (H16) was similar to the experimentally obtained value (DPP-IV IC50=0.66±0.10mgmL-1, p>0.05, n=3). Following simulated gastrointestinal digestion (SGID) of H16 (H16_CorPP), the DPP-IV IC50 value increased (p<0.05) to 0.90±0.07mgmL-1. There was no significant difference between the DPP-IV IC50 value of the SGID of MPI (MPI_CorPP, 0.89±0.11mgmL-1) and that of H16_CorPP. Potent known DPP-IV inhibitory peptide sequences were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) within H16, some of which were also present within H16_CorPP. MPI hydrolysates may be of interest for serum glucose regulation in humans.
Insights
Bovine milk protein isolate (MPI) was hydrolyzed to create peptides that inhibit dipeptidyl peptidase IV (DPP-IV). Increased enzyme concentration and hydrolysis time reduced DPP-IV inhibition, suggesting potential for serum glucose regulation.
Area of Science:
- Food Science and Technology
- Biochemistry
- Nutraceuticals
Background:
- Dipeptidyl peptidase IV (DPP-IV) plays a role in glucose metabolism.
- Milk protein hydrolysates are explored for bioactive peptide generation.
- Understanding hydrolysis conditions is key to optimizing peptide bioactivity.
Purpose of the Study:
- To investigate the release of DPP-IV inhibitory peptides from bovine milk protein isolate (MPI) using trypsin hydrolysis.
- To optimize hydrolysis conditions for maximizing DPP-IV inhibitory activity.
- To assess the stability of inhibitory peptides during simulated gastrointestinal digestion.
Main Methods:
- A 3-factor, 3-level Design of Experiments (DOE) was employed, varying temperature, enzyme-to-substrate ratio (E:S), and hydrolysis time.
- Response Surface Methodology (RSM) was used to predict optimal hydrolysis conditions.
- Liquid chromatography-tandem mass spectrometry (LC-MS/MS) identified peptide sequences.
- Simulated gastrointestinal digestion (SGID) assessed peptide stability.
Main Results:
- Hydrolysis conditions significantly impacted DPP-IV inhibitory activity (IC50).
- Increased E:S and hydrolysis time decreased DPP-IV IC50, indicating enhanced inhibition.
- Optimal conditions predicted by RSM yielded potent DPP-IV inhibition, confirmed experimentally.
- Inhibitory activity slightly increased after simulated gastrointestinal digestion, with identified peptides remaining intact.
Conclusions:
- Optimized trypsin hydrolysis of MPI can generate potent DPP-IV inhibitory peptides.
- These peptides show stability during simulated digestion.
- MPI-derived hydrolysates hold promise for managing serum glucose levels.
Related Concept Videos
01:02Protein Digestion
01:23Dipeptidyl Peptidase 4 Inhibitors
01:15Hydrolysis
Hydrolysis is a chemical reaction in which the addition of water breaks down a polymer into its simpler monomer units. For example, peptides break into amino acids, carbohydrates into simple sugars, and DNA into nucleotides. Enzymes often facilitate these processes.
Hydrolysis Reverses Dehydration Synthesis
Complex carbohydrates can be broken down by breaking the bonds between individual sugar units. The reaction breaks a glycosidic bond as water is added to the compound. The...