title: Purification and identification of Se-containing antioxidative peptides from enzymatic hydrolysates of Se-enriched brown rice protein.
abstract: As a further study of Se-containing proteins (Se-Pro) derived from Se-enriched brown rice (Se-BR), this paper aimed to purify and identify Se-containing antioxidative peptides (Se-antioxi-Peps) from Se-Pro hydrolysates. The total Se content in Se-BR was 6.26μg/g DW, and selenocystine, Se-methylselenocysteine, and selenomethionine were identified as the main organic Se species by high-performance liquid chromatography-inductively coupled plasma mass spectrometry. Se-Pro was extracted and hydrolyzed by four types of proteases, and Alcalase was chosen as the optimum enzyme according to the degree of hydrolysis (DH). The hydrolysate with 17.08% DH possessing the highest DPPH radical scavenging activity was separated into five fractions (F1 to F5). Fractions F3 to F5, which had high antioxidative activities, were further separated. Sub-fractions F3-3, F4-2, and F5-1 were chosen to evaluate antioxidative activities and analyze Se species. The Se-antioxi-Pep with the sequence SeMet-Pro-Ser was identified by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry.
authors.affiliation: College of Food Science and Technology, Henan University of Technology, Zhengzhou 450001, China.
authors.forename: Kunlun
authors.initials: K
authors.lastname: Liu
authors.affiliation: College of Food Science and Technology, Henan University of Technology, Zhengzhou 450001, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: College of Food Science and Technology, Henan University of Technology, Zhengzhou 450001, China. Electronic address: fushengc@haut.edu.cn.
authors.forename: Fusheng
authors.initials: F
authors.lastname: Chen
authors.affiliation: College of Food Science and Engineering, Nanjing University of Finance and Economics/The Jiangsu Province Center of Cooperative Innovation for Modern Grain Circulation and Security, Nanjing 210023, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Fang
mesh_terms: D000975:Antioxidants / Q000302:isolation & purification*; D001713:Biphenyl Compounds / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D003553:Cystine / Q000031:analogs & derivatives* / Q000302:isolation & purification; D006868:Hydrolysis; D016566:Organoselenium Compounds / Q000302:isolation & purification*; D012275:Oryza / Q000737:chemistry*; D010447:Peptide Hydrolases / Q000737:chemistry*; D010455:Peptides / Q000032:analysis*; D010851:Picrates / Q000737:chemistry; D011492:Protein Hydrolysates / Q000737:chemistry*; D012645:Selenomethionine / Q000302:isolation & purification*; D021241:Spectrometry, Mass, Electrospray Ionization; D013054:Spectrophotometry, Atomic; D013481:Superoxides / Q000737:chemistry
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D016566:Organoselenium Compounds; D010455:Peptides; D010851:Picrates; D011492:Protein Hydrolysates; D013481:Superoxides; C009226:selenocystine; D003553:Cystine; D012645:Selenomethionine; C004931:1,1-diphenyl-2-picrylhydrazyl; D010447:Peptide Hydrolases
keywords: Antioxidative activity; Brown rice; Enzymatic hydrolysis; Peptide; Selenium