Using cDNA-AFLP technique, a specific fragment was isolated from cucumber cultivar Changchun mici possessing chilling tolerance induced at low temperature （15℃）. This fragment, named cctr 132, could not be induced ...Using cDNA-AFLP technique, a specific fragment was isolated from cucumber cultivar Changchun mici possessing chilling tolerance induced at low temperature （15℃）. This fragment, named cctr 132, could not be induced in the chilling sensitive cucumber cultivar Beijing jietou. After recovering the fragment, sequencing and translating, the results of blastx and blastp in GenBank of NCBI indicated that CCTR132 had 88.37% identities and 100% positives with Oryza sativa putative lysine decarboxylase-like protein respectively, and PGGXGTXXE, the putative conserved domain of lysine decarboxylase family, was detected from CCTR132, suggesting the cucumber chilling tolerance during germination is related to the expression of the lysine decarboxylase gene.展开更多
Cadaverine is the key monomer for the synthesis of nylon 5X.Efficient and alkaline stable lysine decarboxylases are highly desirable for cadaverine production as the reaction pH increasing from 6.3 to 8.5.However,the ...Cadaverine is the key monomer for the synthesis of nylon 5X.Efficient and alkaline stable lysine decarboxylases are highly desirable for cadaverine production as the reaction pH increasing from 6.3 to 8.5.However,the most studied lysine decarboxylase CadA(E.coli)lost almost all activity at pH 8.0,which is the foremost challenge for the industrial-cadaverine production.In this study,we first found that the Na^(+)-microenvironment significantly improved the alkaline stability of the disulfide engineered lysine decarboxylaseΔLdcEt3(P233C/L628C)(half-life 362 h),compared to the conventional buffer(half-life 0.66 h)at pH 8.0.Meanwhile,the whole-cell conversion efficiency of the industrial-grade L-lysine withΔLdcEt3 could reach up to 99%in 2 h in the fermenter.Experi-mental investigation and molecular dynamics confirmed that Na^(+)-microenvironment could improve active-aggregation state and affect secondary structure ofΔLdcEt3.Therefore,Na^(+)-microenvironment stabilizesΔLdcEt3 providing a great potential industrial application for high-level cadaverine production.展开更多
花榈木是中国传统中药,其代谢产物常用于治疗跌打损伤,具有重要的药用价值,然而目前人们对花榈木的药用化学成分如生物碱合成并不清楚。本研究对花榈木不同组织进行了代谢组和转录组学分析,结果表明花榈木中含有的生物碱大部分属于喹诺...花榈木是中国传统中药,其代谢产物常用于治疗跌打损伤,具有重要的药用价值,然而目前人们对花榈木的药用化学成分如生物碱合成并不清楚。本研究对花榈木不同组织进行了代谢组和转录组学分析,结果表明花榈木中含有的生物碱大部分属于喹诺里西啶类生物碱(Quinolizidine Alkaloids,QA)。进一步分析发现,QA生物合成的2个关键酶,赖氨酸脱羧酶(LDC)和铜胺氧化酶(CAO)在生物碱合成中起重要作用。结合花榈木转录组结果对其编码基因克隆,得到了1290 bp、2268 bp CDS序列,分别命名为OhpLDC和OhpCAO1。生物信息学分析结果表明,OhpLDC和OhpCAO1编码的蛋白质相对分子质量分别为4.63×10^(4)和8.44×10^(4),均无跨膜区域和信号肽。OhpLDC编码的氨基酸序列具有保守的底物结合位点Phe340,分析发现OhpLDC与豆科植物中的LDC基因在进化上具有较近的亲缘关系。OhpCAO1编码的氨基酸序列中具有保守结构域“NY-Y”,以及3个组氨酸保守位点,与狭叶羽扇豆的CAO1亲缘关系最近。本研究结果为解析花榈木QA的生物合成途径提供了重要基础。展开更多
基金This work was partially supported by grants from National Hi-11ech R&D Program(2004241120)the National Natural Science Foundation of China(30470120)Ministry of Agriculture Vegetable Genetic and Physiological Key Laboratory.
文摘Using cDNA-AFLP technique, a specific fragment was isolated from cucumber cultivar Changchun mici possessing chilling tolerance induced at low temperature （15℃）. This fragment, named cctr 132, could not be induced in the chilling sensitive cucumber cultivar Beijing jietou. After recovering the fragment, sequencing and translating, the results of blastx and blastp in GenBank of NCBI indicated that CCTR132 had 88.37% identities and 100% positives with Oryza sativa putative lysine decarboxylase-like protein respectively, and PGGXGTXXE, the putative conserved domain of lysine decarboxylase family, was detected from CCTR132, suggesting the cucumber chilling tolerance during germination is related to the expression of the lysine decarboxylase gene.
基金supported by the National Natural Science Foundation of China (grant number 22078346)Beijing Nova Program of Science and Technology (Z201100006820141)+4 种基金Innovation Academy for Green Manufacture, CAS (IAGM2020C19)Natural Science Foundation of Beijing (2204097)Henan Key Research and Development Project (202102210046)Hebei Provincial Natural Science Foundation (B2020103010)the CAS Pioneer Hundred Program。
文摘Cadaverine is the key monomer for the synthesis of nylon 5X.Efficient and alkaline stable lysine decarboxylases are highly desirable for cadaverine production as the reaction pH increasing from 6.3 to 8.5.However,the most studied lysine decarboxylase CadA(E.coli)lost almost all activity at pH 8.0,which is the foremost challenge for the industrial-cadaverine production.In this study,we first found that the Na^(+)-microenvironment significantly improved the alkaline stability of the disulfide engineered lysine decarboxylaseΔLdcEt3(P233C/L628C)(half-life 362 h),compared to the conventional buffer(half-life 0.66 h)at pH 8.0.Meanwhile,the whole-cell conversion efficiency of the industrial-grade L-lysine withΔLdcEt3 could reach up to 99%in 2 h in the fermenter.Experi-mental investigation and molecular dynamics confirmed that Na^(+)-microenvironment could improve active-aggregation state and affect secondary structure ofΔLdcEt3.Therefore,Na^(+)-microenvironment stabilizesΔLdcEt3 providing a great potential industrial application for high-level cadaverine production.
文摘花榈木是中国传统中药,其代谢产物常用于治疗跌打损伤,具有重要的药用价值,然而目前人们对花榈木的药用化学成分如生物碱合成并不清楚。本研究对花榈木不同组织进行了代谢组和转录组学分析,结果表明花榈木中含有的生物碱大部分属于喹诺里西啶类生物碱(Quinolizidine Alkaloids,QA)。进一步分析发现,QA生物合成的2个关键酶,赖氨酸脱羧酶(LDC)和铜胺氧化酶(CAO)在生物碱合成中起重要作用。结合花榈木转录组结果对其编码基因克隆,得到了1290 bp、2268 bp CDS序列,分别命名为OhpLDC和OhpCAO1。生物信息学分析结果表明,OhpLDC和OhpCAO1编码的蛋白质相对分子质量分别为4.63×10^(4)和8.44×10^(4),均无跨膜区域和信号肽。OhpLDC编码的氨基酸序列具有保守的底物结合位点Phe340,分析发现OhpLDC与豆科植物中的LDC基因在进化上具有较近的亲缘关系。OhpCAO1编码的氨基酸序列中具有保守结构域“NY-Y”,以及3个组氨酸保守位点,与狭叶羽扇豆的CAO1亲缘关系最近。本研究结果为解析花榈木QA的生物合成途径提供了重要基础。
