Major peptides from amaranth (Amaranthus cruentus) protein inhibit HMG-CoA reductase activity

• Published in: International journal of molecular sciences Vol. 16; no. 2; pp. 4150 - 4160
• Main Authors: Soares, Rosana Aparecida Manólio, Mendonça, Simone, de Castro, Luíla Ívini Andrade, Menezes, Amanda Caroline Cardoso Corrêa Carlos, Arêas, José Alfredo Gomes
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 16-02-2015; MDPI
• Subjects: amaranth; Amaranthus - metabolism; Amino Acid Sequence; Amino acids; bioactive peptides; Chromatography, High Pressure Liquid; Chromatography, Reverse-Phase; de novo sequencing; Enzyme Inhibitors - chemistry; Enzyme Inhibitors - isolation & purification; Enzyme Inhibitors - metabolism; Enzymes; HMG-CoA reductase activity; Hydroxymethylglutaryl CoA Reductases - chemistry; Hydroxymethylglutaryl CoA Reductases - metabolism; mass spectrometry; Peptides; Peptides - chemistry; Peptides - isolation & purification; Peptides - metabolism; Plant Extracts - metabolism; Protein Binding; Proteins; Spectrometry, Mass, Electrospray Ionization; Spectrum analysis; Studies
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms16024150

The objective of this study was to identify the major peptides generated by the in vitro hydrolysis of Amaranthus cruentus protein and to verify the effect of these peptides on the activity of 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMG-CoA reductase), a key enzyme in cholesterol biosynthesis. A protein isolate was prepared, and an enzymatic hydrolysis that simulated the in vivo digestion of the protein was performed. After hydrolysis, the peptide mixture was filtered through a 3 kDa membrane. The peptide profile of this mixture was determined by reversed phase high performance chromatography (RP-HPLC), and the peptide identification was performed by LC-ESI MS/MS. Three major peptides under 3 kDa were detected, corresponding to more than 90% of the peptides of similar size produced by enzymatic hydrolysis. The sequences identified were GGV, IVG or LVG and VGVI or VGVL. These peptides had not yet been described for amaranth protein nor are they present in known sequences of amaranth grain protein, except LVG, which can be found in amaranth α‑amylase. Their ability to inhibit the activity of HMG-CoA reductase was determined, and we found that the sequences GGV, IVG, and VGVL, significantly inhibited this enzyme, suggesting a possible hypocholesterolemic effect.