Enzymatic release of dipeptidyl peptidase‐4 inhibitors (gliptins) from pigeon pea (Cajanus cajan) nutrient reservoir proteins: In silico and in vitro assessments

Abstract

Abbreviations: ANS, 8-anilino-1-naphthalenesulphonic acid; BSA, bovine serum albumin; DPP-4, dipeptidyl peptidase-4; GIP, glucose-dependent insulinotropic polypeptide; GLP-1, glucagon-like peptide-1; GRAVY, grand average of hydropathicity; OPA, o-phthalaldehyde; pI, theoretical isoelectric point; RMSE, root mean square error; T2DM, type 2 diabetes mellitus; UPLC, ultra-performance liquid chromatography. AbstractIn silico and in vitro parameters were used to assess the potential of pigeon pea (Cajanus cajan) nutrient reservoir proteins as sources of dipeptidyl peptidase (DPP)-4 inhibitors. In silico, 40 pigeon pea proteins evaluated had 46% of amino acids associated with DPP-4 inhibition. After virtual hydrolysis, pepsin had the highest frequency of release and bioactivity of released DPP-4 inhibiting peptides, compared to papain and thermolysin. In vitro, thermolysin released the most active DPP-4 inhibitors.The protein hydrolysates contained similar amino acids but different particle sizes.Thus, the bioactivity patterns are attributable to the different nature and behavior of proteins/peptides under actual and virtual conditions. Using eight physicochemical variables, a random forest model with moderate prediction accuracy was developed for predicting DPP-4 inhibitory activity of papain hydrolysates. The findings demonstrate that proteins from pigeon pea are precursors of DPP-4 inhibitors, with potential use in formulating functional food for managing type 2 diabetes. | In silico analysis of physicochemical properties of pigeon pea proteinsPhysicochemical properties of the 40 mature pigeon pea proteins/ domains and BSA were calculated using the ProtParam feature of UniProtKB. The properties include the protein chain length, theoretical isoelectric point (pI), molecular weight, grand average of K E Y W O R D S bioactive peptides, bioinformatics, Cajanus cajan, dipeptidyl peptidase-4, in silico, pigeon pea S U PP O RTI N G I N FO R M ATI O N Additional supporting information may be found online in the Supporting Information section at the end of the article. How to cite this article: Boachie RT, Okoro FL, Imai K, et al. Enzymatic release of dipeptidyl peptidase-4 inhibitors (gliptins) from pigeon pea (Cajanus cajan) nutrient reservoir proteins: In silico and in vitro assessments. J Food Biochem.

Bioinformatics of edible yellow mealworm (Tenebrio molitor) proteome reveal the cuticular proteins as promising precursors of dipeptidyl peptidase‐IV inhibitors

“…Similar result was recently reported for pigeon pea protein precursors of DPP-IV inhibitors (Boachie et al, 2019). Similar result was recently reported for pigeon pea protein precursors of DPP-IV inhibitors (Boachie et al, 2019).…”

“…In silico prediction of the preferred protease was however not validated in vitro using the extracted mealworm proteins. Similar result was recently reported for pigeon pea protein precursors of DPP-IV inhibitors (Boachie et al, 2019). This discrepancy can be because the virtual digestion uses the linear protein structure due to lack of bioinformatics tools that simulate enzyme-protein interactions occurring during in vitro digestion of 3-dimensional proteins.…”

“…Moreover, the mealworm proteins are not completely solubilized at the acidic pH condition of pepsin in vitro, which will hinder accessibility of the protease to cleavage sites on the proteins (Boachie et al, 2019). Nonetheless, the bioinformatics approach systematically guided the selection of cuticular proteins as the most promising precursors of DPP-IV inhibitors.…”

Identification and Antimicrobial Activity of Medium-Sized and Short Peptides from Yellowfin Tuna (Thunnus albacares) Simulated Gastrointestinal Digestion

“…This result, compared with the GRAVY index for medium-sized peptides, highlighted that the use of a mixture of pepsin and pancreatin was able to generate more hydrophobic and aromatic short peptides, containing for instance Leu, Ile, Phe and Tyr. This behavior was already demonstrated in pigeon pea digest [ 50 , 51 ].…”

Germination alters the microstructure, in vitro protein digestibility, α‐glucosidase and dipeptidyl peptidase‐IV inhibitory activities of bioaccessible fraction of pigeon pea (Cajanus cajan) seeds

“…Pigeon pea ( Cajanus cajan ) is an underutilized legume with a potential to contribute in achieving food security. Pigeon pea seeds contain up to 24% proteins on a dry weight basis (Singh, 2016), and the proteins are rich in lysine (Boachie et al, 2019; Krishnan et al, 2017), the limiting amino acids of cereals. However, as with other legume proteins, the digestibility and bioaccessibility of pigeon pea seed proteins are impaired by the complex microstructure and presence of interfering compounds in the seed matrix.…”