Prediction of Bioactive Peptides From Chicken Feather and Pig Hair Keratins Using In Silico Analysis Based on Fragmentomic Approach

The biological role of prolyl oligopeptidase and the procognitive potential of its peptidic inhibitors from food proteins

Prolyl oligopeptidase (POP) is a conserved serine protease belonging to proline-specific peptidases. It has both enzymatic and non-enzymatic activity and is involved in numerous biological processes in the human body, playing a role in e.g., cellular growth and differentiation, inflammation, as well as the development of some neurodegenerative and neuropsychiatric disorders. This article describes the physiological and pathological aspects of POP activity and the state-of-art of its peptidic inhibitors originating from food proteins, with a particular focus on their potential as cognition-enhancing agents. Although some milk, meat, fish, and plant protein-derived peptides have the potential to be applied as natural, procognitive nutraceuticals, their effectiveness requires further evaluation, especially in clinical trials. We demonstrated that the important features of the most promising POP-inhibiting peptides are very short sequence, high content of hydrophobic amino acids, and usually the presence of proline residue.

Peptidomic Characteristic of Peptides Generated in Dry-Cured Loins with Probiotic Strains of LAB during 360-Days Aging

Peptidomics refers to the comprehensive profiling of endogenous peptides obtained from biological sources. The formation of endogenous peptides is dependent on not only endogenous factors but also exogenous factors such as microbial proteases or process conditions, including fermentation. This study analyzed the probiotic strains of Lactobacillus rhamnosus LOCK900 (LOCK), Bifidobacterium animalis ssp. lactis BB-12 (BB12), and potential probiotic Lactobacillus acidophilus Bauer Ł0938 (BAUER) to assess their ability of fermentation and peptide production in dry-cured pork loin. The peptides obtained after in vitro digestion were characterized by liquid chromatography–tandem mass spectrometry. Based on the sequences identified, the degree of similarity or differences between the peptides was determined and presented graphically on the factor plane. The charts showed that the meat products aged for 180 and 270 days were the most diverse when BB12 or BAUER were used as starter cultures. Myosin and keratin were identified as the most likely precursors of bioactive peptides in products obtained using this strain of lactic acid bacteria (LAB). The knowledge acquired from this study may contribute to the design of functional meat products as the results revealed not only the peptidogenic potential of the LAB strains indicated on their beneficial effect on the bioactivity of peptides.