Kinetics of acetylcholinesterase inhibition by hemp seed protein‐derived peptides

Abstract

The aim of this work was to enhance the acetylcholinesterase (AChE)‐inhibitory activity of a pepsin‐produced hemp seed protein hydrolysates (HPH) through reverse‐phase HPLC separation followed by identification of peptide sequences present in the most active fraction. The HPH was separated into eight fractions (F1–F8) with F7 exhibiting significantly (p < 0.05) the strongest (97.5%) in vitro inhibition of electric eel AChE (eeAChE) activity in comparison to 53.8% for HPH. The HPH consisted mostly of low molecular weight peptides of < 11 amino acid residues and most contained at least one hydrophobic amino acid. Kinetics of enzyme inhibition revealed a mixed‐type inhibition of eeAChE activity by HPH whereas F7 acted through an uncompetitive mode; in contrast inhibition of human AChE by HPH and F7 was uncompetitive. The stronger inhibitory potency of the F7 peptides fraction against both enzymes was confirmed through reduced maximal velocity, catalytic efficiency, and inhibition constant values when compared to the HPH. Practical applications The use of natural products for the prevention or treatment of human diseases continues to be an area of intense research activities. Food protein‐derived peptides obtained through enzymatic hydrolysis of hemp seed proteins were shown in vitro to be strong inhibitors of activities of both the eel and human forms of acetylcholinesterase (AChE). AChE is an important therapeutic target because excessive activity of this enzyme is a causative factor of neurodegenerative diseases such as dementia and Alzheimer's. This work showed that peptides in the most active fraction are small in sizes, which may favor their absorption into blood circulation and possible permeation of the blood–brain barrier. Therefore, the hemp seed peptides are potential agents that can be used to formulate functional foods and nutraceuticals against neurodegenerative diseases.

Effect of Protease Type and Peptide Size on the In Vitro Antioxidant, Antihypertensive and Anti-Diabetic Activities of Eggplant Leaf Protein Hydrolysates

“…Interestingly, PH and TH had the lowest number and longest length of identifiable peptides, which reflects the lower DH when compared to AH and CH. A previous study suggested that low molecular weight peptides have greater chance to pass through the gastrointestinal tracts faster than the peptides with bigger molecular weights, which could enhance bioactive effects [ 34 ]. Based on this principle, the small peptides identified in CH may have stronger bioactive impacts if ingested when compared to the other hydrolysates in this study.…”

“…The method described by Malomo and Aluko [ 34 ] was used to identify the peptide sequences of the protein hydrolysates. Formic acid (0.1% v / v ) was used to dilute the sample to a final concentration of 10 ng/µL.…”

In Vitro Characterization of Fluted Pumpkin Leaf Protein Hydrolysates and Ultrafiltration of Peptide Fractions: Antioxidant and Enzyme-Inhibitory Properties

“…The presence of shorter peptides such as the dipeptides may suggest greater advantages to interact with and neutralize free radicals more effectively to inhibit propagation. In addition, all the identified peptides have molecular weights <500 Da and this may enhance the ease of absorption of the peptides from the gastrointestinal tract and improve in vivo activities [Malomo & Aluko, 2019]. Alcalase and chymotrypsin hydrolysates shared three (PGV, GVP, and RP) common peptides (2 tripeptides and 1 dipeptide) while pepsin and trypsin hydrolysates showed two (STGT and FKA) similar peptides.…”

Identification and Characterization of the Seed Storage Proteins and Related Genes of Cannabis sativa L.

“…In addition, the hydrolysates of plant protein have unique physiological functions (22,(25)(26)(27)(28)(29). After digestion with different proteases, the hydrolysates of HSP were demonstrated to exhibit various physiological activities in vitro as well as in vivo, with hemp proteins short-chain peptides such as WVYY and PSLPA exhibiting antioxidant ability, GVLY and LGV exhibiting anti-hypertension ability, and the hydrolysates exhibiting antiproliferative and hypocholesterolemic activities (30)(31)(32)(33)(34)(35)(36).…”