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• 生物工程 •    下一篇

植物乳杆菌p-8转化亚油酸为共轭亚油酸的分析

赵微1,张峰2,张和平3,赵国芬4   

  1. 1. 内蒙古呼和浩特市赛罕区内蒙古农业大学生命科学学院
    2. 内蒙古农业大学生命科学院
    3. 内蒙古农业大学乳品生物技术与工程教育部重点实验室
    4. 内蒙古呼和浩特市赛罕区鄂尔多斯大街内蒙古农业大学新区生命科学学院
  • 收稿日期:2020-02-25 修回日期:2021-01-25 出版日期:2021-05-25 发布日期:2021-05-26
  • 通讯作者: 赵国芬 E-mail:guofenzhao302@163.com
  • 基金资助:
    植物乳杆菌P-8亚油酸异构酶结构和功能的研究;基于LBL的微囊化重组亚油酸异构酶改性的研究

Conversion of Linoleic Acid to Conjugated Linoleic Acid by Lactobacillus plantarum p-8

Wei ZhaoInner MongoliaAgricultural2,heping zhangInner MongoliaAgricultural   

  • Received:2020-02-25 Revised:2021-01-25 Online:2021-05-25 Published:2021-05-26
  • Contact: Inner MongoliaAgricultural E-mail:guofenzhao302@163.com

摘要: cis9, trans11-Conjugated linoleic acid(c9, t11-CLA)、trans10, cis12-Conjugated linoleic acid(t10, c12-CLA)和trans9, trans11-Conjugated linoleic acid(t9, t11-CLA)是三种主要发挥益生功能的异构体,可由生物转化亚油酸(Linoleic acid,LA)而来。本文研究了植物乳杆菌(Lactobacillus plantarum,L. plantarum)p-8的菌体、菌体破碎液和重组亚油酸异构酶系转化LA为CLA的能力和机制。结果表明:L. plantarum p-8在含有LA的MRS上清液和菌体破碎液体外催化LA时,都可以低效产生c9, t11-CLA、t10, c12-CLA和t9, t11-CLA,但菌体中只有很少的t10, c12-CLA。RT-qPCR结果表明,亚油酸异构酶系的表达水平较低可能是CLA产量较低的原因。独立表达的重组亚油酸异构酶系成员、黄素腺嘌呤二核苷酸(Flavin denine dinucleotide,FAD)和烟酰胺腺嘌呤二核苷酸(Nicotinamide adenine dinucleotide,NAD+)都存在才可完成LA转化为c9, t11-CLA、t10, c12-CLA和t9, t11-CLA,转化过程包含水合、脱氢、双键移位、氧化和脱水反应多步反应。L. plantarum p-8的亚油酸水合酶经同源建模后有三个结构域,底物结合位点与FAD位点位于三个结构域连接处的疏水空腔中,M76和Y180是2个必需基团。

关键词: c9, t11-CLA, t10, c12-CLA, t9, t11-CLA, 脂肪酸水合酶, 原核表达, 同源建模

Abstract: cis9, trans11-Conjugated linoleic acid (c9, t11-CLA), trans10, cis12-Conjugated linoleic acid (t10, c12-CLA) and trans9, trans11-Conjugated linoleic acid (t9, t11-CLA) are three isomers that play probiotic functions, its can produced by bioconversion LA. In this study, the ability and mechanism of conversion LA to CLA by cells, disrupted cells solution and the linoleate isomerase family of Lactobacillus plantarum (L. plantarum) p-8. The result shown that L. plantarum p-8 could low-efficiently produce c9, t11-CLA, t10, c12-CLA and t9, t11-CLA when the MRS medium containing LA and the disrupted cells solution catalyzed LA,and only a small amount of t10, c12-CLA was found in the cells. The result of RT-qPCR shown that, lower expression levels of linoleate isomerase family may be responsible for lower CLA production. Only members of the independently expressed recombinant linoleate isomerase family, Flavin denine dinucleotide (FAD) and Nicotinamide adenine dinucleotide (NAD+) are present to complete conversion LA to c9, t11-CLA, t10, c12-CLA and t9, t11-CLA, and it conversion mechanism includes hydration, dehydrogenation, double bond shift, oxidation and dehydration. Homologous modeling of linoleic acid hydrase has three domains. The substrate binding site and FAD site are located in the hydrophobic cavity at the junction of the three domains. M76 and Y180 are two essential residues.

Key words: cis9, trans11-Conjugated linoleic acid (c9, t11-CLA), trans10, cis12-Conjugated linoleic acid (t10, c12-CLA), trans9, trans11-Conjugated linoleic acid (t9, t11-CLA), Fatty acid hydratase, Prokaryotic expression, Homologous modeling

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