Exploration of Potentially Bioactive Peptides Generated from the Enzymatic Hydrolysis of Hempseed Proteins

The seed of industrial hemp is an underexploited protein source. In view of a possible use in functional foods, a hempseed protein concentrate was hydrolyzed with pepsin, trypsin, pancreatin, or a mixture of these enzymes. A detailed peptidomic analysis using data-dependent acquisition showed that the numbers of peptides identified ranged from 90 belonging to 33 parent proteins in the peptic hydrolysate to 9 belonging to 6 proteins in the pancreatin digest. The peptic and tryptic hydrolysates resulted to be the most efficient inhibitors of 3-hydroxymethyl-coenzyme A reductase activity when tested on the catalytic domain of the enzyme. Using the open access tools PeptideRanker and BIOPEP, a list of potentially bioactive peptides was generated: the alleged activities included the antioxidant property, the glucose uptake stimulating activity, the inhibition of dipeptidyl peptidase-IV and angiotensin-converting enzyme I

Mass Spectrometry-Based Proteomic Approach in <i>Oenococcus oeni</i> Enological Starter

A simple procedure is proposed for selective protein solubilization and trypsin digestion, followed by off-line liquid chromatography–matrix assisted laser desorption ionization mass spectrometry (LC–MALDI MS) analysis of <i>Oenococcus oeni</i> (<i>O. oeni</i>) bacterium. Peptides were identified from tryptic digests using sequencing by tandem mass spectrometry and database searches. Cytoplasmic and membrane related proteins (MRP) were identified in the <i>O. oeni</i> bacterium. MS/MS data analysis points out 13 peptides having one point mutation from 9 proteins. The major microheterogeneity was found for Zn-dependent alcohol dehydrogenase (Zn-ADH, Q04GE6) and 60 kDa chaperonin (GroEL, Q04E64) that are involved in methionine catabolism and post-translational protein folding, respectively. MS/MS data processing also leads to the identification of 34 unique phosphorylation sites from 19 phosphoproteins