title: Purification and characterization of novel antioxidant peptides from enzymatic hydrolysates of tilapia (Oreochromis niloticus) skin gelatin.
abstract: To obtain hydrolysates with high degree of hydrolysis (DH) and scavenging radical activity, tilapia skin gelatin (TSG) was hydrolyzed by properase E and multifect neutral. The optimum hydrolysis condition of each enzyme was determined using the orthogonal experiment, and double-enzyme hydrolysis was further applied. The results showed the tilapia skin gelatin hydrolysate (TSGH) obtained by progressive hydrolysis using multifect neutral and properase E had the highest DH and hydroxyl radical scavenging activity. The IC(50) values of TSGH on scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, superoxide anion radical (·O(2)) and hydroxyl radical (·OH) activities were also determined. TSGH was further purified using gel filtration chromatography, ion exchange chromatography, and RP-HPLC. The peptides were identified using nano-LC-ESI mass spectrometry. Finally, two antioxidant peptides were identified and the amino acid sequences were Glu-Gly-Leu (317.33 Da) and Tyr-Gly-Asp-Glu-Tyr (645.21 Da), respectively. The IC(50) values of two peptides on hydroxyl radical scavenging activities were 4.61 μg mL(-1)and 6.45 μg mL(-1), respectively. Therefore, the results demonstrated that the hydrolysates of TSG prepared by multifect neutral and properase E could serve as a source of peptides with high antioxidant activity. It provided a scientific basis for the preparation of antioxidant peptides.
authors.affiliation: Kunming University of Science and Technology, College of Chemistry and Engineering Kunming, Yunnan 650500, China.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiu
authors.initials: X
authors.lastname: Duan
authors.forename: Yongliang
authors.initials: Y
authors.lastname: Zhuang
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004798:Enzymes / Q000737:chemistry; D029941:Fish Proteins / Q000302:isolation & purification* / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology; D005780:Gelatin / Q000737:chemistry; D006868:Hydrolysis; D017665:Hydroxyl Radical / Q000378:metabolism; D020128:Inhibitory Concentration 50; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D012867:Skin / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013481:Superoxides / Q000378:metabolism; D017210:Tilapia
chemical_list: D000975:Antioxidants; D004798:Enzymes; D029941:Fish Proteins; D016166:Free Radical Scavengers; D010455:Peptides; D013481:Superoxides; D017665:Hydroxyl Radical; D005780:Gelatin