Generation, characterization and molecular binding mechanism of novel dipeptidyl peptidase-4 inhibitory peptides from sorghum bicolor seed protein. (1st February 2022)

• Record Type: Journal Article
• Authors: Majid, Abdul; Lakshmikanth, M.; Lokanath, N.K.; Poornima Priyadarshini, C.G.
• Is Part Of: Food chemistry. Volume 369(2022)
• Publication Date: 2022-02-01
• Subjects: Sorghum bicolor -- DPP-4 -- Bioactive peptides -- Gastrointestinal simulation -- Molecular docking -- Microscale thermophoresis -- Mixed type enzyme kinetics -- Diabetes; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2021.130888
• Languages: English
• ISSNs: 0308-8146

Abstract

Graphical abstract: Highlights: Sorghum protein hydrolysates (SPH) inhibit dipeptidyl peptidase 4 (DPP-4) in vitro. Three novel peptides identified in SPH showed potential DPP-4 inhibitory activity. Peptides showed strong affinity to DPP-4 and mixed type enzyme inhibition kinetics. PEP4 exerted most potent DPP-4 inhibition with an IC50 Value of 8.55 µM. Abstract: Food proteins and their constituent peptides impart huge health benefits besides their nutritional attributes. Sorghum bicolor protein hydrolysates (SPH) and derived bioactive peptides generated by simulated gastrointestinal digestion were studied for DPP-4 inhibitory properties using in vitro and in situ assays. Identified peptides, LSICGEESFGTGSDHIR (PEP1), SLGESLLQEDVEAHK (PEP2) and QLRDIVDK (PEP4) displayed potent DPP-4 inhibition with IC50 values of 73.5, 82.5 and 8.55 µM respectively. DPP-4 inhibition mechanism by the peptides was investigated by DPP4-peptide inhibition kinetics, molecular docking and microscale thermophoresis binding studies. The peptides bound to DPP-4 with micromolar affinities and PEP4 showed significantly increased affinity. The mixed type enzyme inhibition by peptides suggested that the peptides either block the active site of DPP-4 or changes the enzyme conformation via a secondary binding site. Overall, the results demonstrate that sorghum seeds are an adequate source of peptides with DPP-4 inhibitory properties that could be used in functional food formulations.