食品科学 ›› 2019, Vol. 40 ›› Issue (14): 123-129.doi: 10.7506/spkx1002-6630-20180730-359

• 生物工程 • 上一篇    下一篇

利用坛紫菜藻红蛋白制备脯氨酰内肽酶抑制肽

谢雪琼,钟 婵,孙乐常,翁 凌,张凌晶,刘光明,曹敏杰   

  1. 1.集美大学食品与生物工程学院,福建 厦门 361021;2.水产品深加工技术国家地方联合工程研究中心,福建 厦门 361021
  • 出版日期:2019-07-25 发布日期:2019-07-23
  • 基金资助:
    国家自然科学基金面上项目(31772049)

Preparation of Prolyl Endopeptidase Inhibitory Peptides from R-phycoerythrin Hydrolysate of Porphyra haitanensis

XIE Xueqiong, ZHONG Chan, SUN Lechang, WENG Ling, ZHANG Lingjing, LIU Guangming, CAO Minjie   

  1. 1. College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; 2. National & Local Joint Engineering Research Center of Processing Technology for Aquatic Products, Xiamen 361021, China
  • Online:2019-07-25 Published:2019-07-23

摘要: 以坛紫菜(Porphyra haitanensis)为原料,通过硫酸铵盐析和DEAE-Sepharose阴离子交换柱层析等方法分离纯化得到一种高纯度藻红蛋白(R-phycoerythrin,R-PE)(A565 nm/A280 nm=5.4)。利用胃、肠液消化酶对R-PE进行酶解制备脯氨酰内肽酶(prolyl endopeptidase,PEP)抑制肽。酶解条件为:1)胃蛋白酶与R-PE比例0.5%(m/m),酶解时间30 min,pH 1.2,温度37 ℃;2)胰蛋白酶和胰凝乳蛋白酶质量比为1∶1的混合酶,其与R-PE比例0.25%(m/m),酶解时间30 min,pH 7.5,温度37 ℃。Tricine-十二烷基硫酸钠-聚丙烯酰氨凝胶电泳分析发现,经两步酶解,R-PE被完全降解。采用凝胶过滤色谱法测得R-PE水解液中分子质量在3 kDa以下的小肽含量为86.06%。R-PE水解液对PEP抑制水平IC50为136.35 μg/mL。酶抑制动力学研究发现,R-PE水解液对PEP表现为可逆的非竞争性抑制作用,抑制常数Ki为14 μg/mL。本研究利用坛紫菜R-PE制备活性高的PEP抑制肽,将为坛紫菜深加工及高值化利用提供一定的理论参考。

关键词: 坛紫菜, 藻红蛋白, 脯氨酰内肽酶抑制活性, 分子质量分布, 抑制动力学

Abstract: In this paper, R-phycoerythrin with relatively high purity (A565 nm/A280 nm = 5.4) was obtained from Porphyra haitanensis by ammonium sulfate fractionation and DEAE-Sepharose anion exchange chromatography. Prolyl endopeptidase (PEP) inhibitory peptides from R-phycoerythrin were prepared by two-step enzymatic digestion with gastrointestinal fluid proteases. Optimal hydrolysis conditions were determined as sequential hydrolysis with 0.5% pepsin at an enzyme-tosubstrate ratio of for 30 min at an initial pH of 1.2 and 37 ℃ followed by a 1:1 mixture of trypsin and chymotrypsin at an enzyme-to-substrate ratio of 0.25% for 30 min at pH 7.5 and 37 ℃. Tricine-SDS-PAGE showed that R-phycoerythrin was completely degraded by two-step enzymatic hydrolysis. Gel filtration chromatography analysis revealed that fractions with molecular mass lower than 3 kDa accounted for 86.06% of the total peptides. The half-maximum inhibitory concentration (IC50) of R-phycoerythrin hydrolysate toward PEP was 136.35 μg/mL. Inhibition kinetic study revealed that the hydrolysate acted as a noncompetitive inhibitor and the constant of inhibition (Ki) was 14 μg/mL. Successful preparation of R-phycoerythrin peptides with potential PEP inhibitory activity provides a theoretical rationale for the processing and utilization of P. haitanensis.

Key words: Porphyra haitanensis, R-phycoerythrin, PEP inhibitory activity, molecular mass distribution, inhibition kinetics

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