播娘蒿叶绿体型△12脱饱和酶的功能研究  

Further functional characterization of a chloroplast△12 fatty acid desaturases from Descurainia sophia

作　　者：李湘[1] 叶华勋[1] 兰利琼[1] 傅华龙[1] 汪乐霓[1] 陈波[1] 卿人韦[1] 

机构地区：[1]四川大学生命科学学院,成都610064

出　　处：《四川大学学报（自然科学版）》2012年第6期1375-1380,共6页Journal of Sichuan University(Natural Science Edition)

基　　金：国家高技术发展计划(863计划)(2007AA09Z427;2008AA10Z409);教育部留学回国人员启动基金(20071108-18-8);国家自然科学基金面上项目(40976092)

摘　　要：本文应用RT-PCR和RACE方法扩增出了的播娘蒿叶绿体型△12脱饱和酶(Ds-FAD2CHL)全长cDNA,其完整编码框为1344 bp,编码447个氨基酸;该基因ORF在酵母Saccharamyces cerevisiae中的表达阐明其功能为将18:1^(△9)脱饱和生成亚油酸(18:2^(△9,12));进一步切除叶绿体信号肽后的脱饱和酶在酵母中把18:1^(△9)脱饱和生成18:2^(△9,12)的效率提高了3.72%;通过GC/MS分析转基因酵母的磷脂及酰基辅酶A库发现,该脱饱和酶的作用底物为磷脂,而不是以酰基辅酶A形式结合的脂肪酸.A chloroplast△12 fatty acid desaturases gene from Descurainia Sophia （DsFAD2CHL） was isolated by RT-PCR and RACE. It has an open reading frame of 1344 bp, which encodes 447 amino acids. Expression of this cDNA in Saccharamyces cerevisiae revealed that the desaturase had a function that introduce an double bond into 18：1△9 to produce linoleic acid （18.2△9,l2）, and the enzyme removing a plastidial signal peptide had a 3.72% higher desaturation conversion rate. Further phospholipids and acyl-CoAs pool analysis by GC/MS showed that the substrate of this enzyme was combined with phos- pholipids but not acyl-CoA.

关 键 词：播娘蒿 脂肪酸脱饱和酶 底物类型 酰基辅酶A库 

分 类 号：Q786[生物学—分子生物学]