Tuber storage proteins as potential precursors of bioactive peptides : an in silico analysis

Abstract

In silico analysis was used to evaluate storage proteins from plant tubers as potential precursors of bioactive peptides after simulated gastrointestinal digestion. Proteins derived from potato (patatins), sweet potato (sporamins), yam (dioscorins) and taro (tarin) were subjected to in silico gastrointestinal digestion with a combination of pepsin, chymotrypsin and trypsin in the BIOPEP database which led to the release of 387 peptide fragments which were predicted to have bioactivities such as dipeptidyl peptidase IV (DPP-IV), angiotensin converting enzyme (ACE), antioxidative and antithrombotic activities. Prediction of antimicrobial activity of the released peptides using the collection of antimicrobial peptides (CAMP) database indicated 28 peptides as potential antimicrobial peptides (AMPs) with varied percentage similarity with known AMPs in antimicrobial peptide database (APD). Furthermore, 32 peptides with potential anticancer activity were predicted using the AntiCP database while nine peptides were predicted to be bioactive according to peptideRanker but the precise bioactivity was not identified. The potato-derived proteins seem to be the richest source of DPP-IV inhibitory and antimicrobial peptides while yam-derived proteins yielded the highest amount of antihypertensive and anticancer peptides. The data suggests that storage proteins from the selected plants could release an array of non-toxic and species-specific bioactive peptides with health promoting effects suggesting that these tubers might serve as functional foods.