title: Major peptides from amaranth (Amaranthus cruentus) protein inhibit HMG-CoA reductase activity.
abstract: 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.
authors.affiliation: Faculty of Public Health, University of São Paulo, Av. Dr. Arnaldo, 715, São Paulo 01246-904, SP, Brazil. rosanaso@usp.br.
authors.forename: Rosana Aparecida Manólio
authors.initials: RA
authors.lastname: Soares
authors.affiliation: EMBRAPA (Brazilian Corporation of Agricultural Research), PqEB, Brasília 70770-200, DF, Brazil. doutorasimone@gmail.com.
authors.forename: Simone
authors.initials: S
authors.lastname: Mendonça
authors.affiliation: Faculty of Public Health, University of São Paulo, Av. Dr. Arnaldo, 715, São Paulo 01246-904, SP, Brazil. luila.andrade1@gmail.com.
authors.forename: Luíla Ívini Andrade
authors.initials: LÍ
authors.lastname: de Castro
authors.affiliation: Faculty of Public Health, University of São Paulo, Av. Dr. Arnaldo, 715, São Paulo 01246-904, SP, Brazil. amandacarlos@usp.br.
authors.forename: Amanda Caroline Cardoso Corrêa Carlos
authors.initials: AC
authors.lastname: Menezes
authors.affiliation: Faculty of Public Health, University of São Paulo, Av. Dr. Arnaldo, 715, São Paulo 01246-904, SP, Brazil. jagareas@usp.br.
authors.forename: José Alfredo Gomes
authors.initials: JA
authors.lastname: Arêas
mesh_terms: D027721:Amaranthus / Q000378:metabolism*; D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D006903:Hydroxymethylglutaryl CoA Reductases / Q000737:chemistry / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D010936:Plant Extracts / Q000378:metabolism; D011485:Protein Binding; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D004791:Enzyme Inhibitors; D010455:Peptides; D010936:Plant Extracts; D006903:Hydroxymethylglutaryl CoA Reductases