重组聚半乳糖醛酸酶PGB的生化特征及其酶解产物活性分析  

Biochemical characterization of the recombinant polygalacturonase PGB and the activity analysis of its enzymatic hydrolysis product

作　　者：谌新然 黄永生 田康明 金鹏[1] 董自星 刘晓光 路福平 王正祥[1,2] 

机构地区：[1]天津科技大学化工与材料学院生物化工系,天津300457 [2]天津科技大学生物工程学院与工业发酵微生物教育部重点实验室,天津300457

出　　处：《食品工业科技》2017年第23期119-123,共5页Science and Technology of Food Industry

摘　　要：解析重组聚半乳糖醛酸酶PGB的酶学性质,研究PGB制备的果胶水解物的基本成分和生物学活性。通过摇瓶发酵制备聚半乳糖醛酸酶酶液,研究其基本酶学性质。再在最优作用条件下对果胶进行水解,并考察水解产物的组成、抗菌活性和抗氧化活性。在摇瓶发酵水平,黑曲霉聚半乳糖醛酸酶PGB的酶活达到10790 U/m L;该酶的最适作用温度和p H分别为55℃和5.0;在40℃或p H4.0~6.0条件下具有较好稳定性。Mg^(2+)和Cu^(2+)对其活性有促进作用,K^+、Ca^(2+)、Zn^(2+)、Mn^(2+)、Co^(2+)、Fe^(3+)和Fe^(2+)等对其活性均有不同程度的抑制作用;它对低酯果胶的K_m和V_(max)分别是0.756 mg/m L和9.225 mg/(m L·min)。高效阴离子交换色谱-脉冲安培检测法(HPAEC-PAD)的分析表明,PGB对果胶的酶解产物是半乳糖醛酸单体和聚合度2~4为主的寡聚半乳糖醛酸,它对金黄色葡萄球菌的生长有显著抑制作用,其最小抑菌浓度和抗氧化活性分别为0.64 mg/m L和6.125 U/m L。To analyze the enzymatic properties of recombinant polygalacturonase PGB and＇to study the compositions and biological activities of pectin hydrolysa[e prepared by PGB.Polygalacturonase was prepared by shake flask fermentation and its enzymatic properties were investigated.Pectin was hydrolyzed by PGB under optimum conditions, followed by investigation of its compositions, and antioxidant and antibacterial activities. At the shake flask fermentation level, the activity of PGB reached 10790 U/mL.Its optimum temperature and pH was 55 % and 5.0 ,respectively.And it was quite stable at 40℃ or pH4.0 6.0. Mg^2＋ and Cu^2＋enhanced its activity, while K ＋ , Ca^2＋ , Zn^2＋ , Mn^2＋ , Co2 ~ , Fe3＋ and Fe^2＋ had different inhibitory effects on its activity.The Km and Vmax PGB toward low-ester pectin was determined to be 0.756 mg/mL and 9.225 mg/（ mL·min）.After hydrolyzed by PGB, pectin hydrolysate was identified as galacturonic acid and oligogalacturonic acid with a polymerization degree of 2 to 4 by high performance anion exchange chromatography- pulsed amperometric detector （ HPAEC- PAD ）. This oligomer significantly inhibited the growth of Staphylococcus aureus, and its minimum inhibitory concentration and antioxidant activity was 0.64 mg/mL and 6.125 U/mL,respectively.

关 键 词：聚半乳糖醛酸酶 生化特征 果胶 寡聚半乳糖醛酸 

分 类 号：TS245.9[轻工技术与工程—制糖工程]