玉米非特异性脂转移蛋白的cDNA克隆和表达及表达产物的钙调素结合活性分析  

Cloning and Expression of cDNA for Maize Nonspecific Lipid Transfer Protein as Well as Calmodulin-Binding Activity Analysis of the Expression Product

作　　者：白文艳[1] 赵立青[1] 李振鹏[1] 谢万钦[1] 赵玉龙[1] 李翠凤[1] 

机构地区：[1]南开大学生命科学学院生物化学与分子生物学系,天津300071

出　　处：《植物生理与分子生物学学报》2006年第5期570-576,共7页Journal Of Plant Physiology and Molecular Biology

基　　金：国家自然科学基金项目(No.30370733)资助~~

摘　　要：用RT-PCR法克隆了成熟的玉米非特异性脂转移蛋白的cDNA,将它连接到表达质粒上并转化至大肠杆菌中表达。以钙调素凝胶覆盖法和钙调素亲和层析下拉实验对表达产物进行分析,证明它具有结合钙调素的活性,并且这种结合不依赖于Ca2+,与前期研究中钙调素结合蛋白-10和拟南芥非特异性脂转移蛋白1的结合特性相同。采用基因删除和缺失突变的方法研究玉米非特异性脂转移蛋白与钙调素结合的结构域,结果表明钙调素结合于47～60位氨基酸,预测的蛋白质二级结构为碱性双亲α-螺旋结构。Maize nonspecific lipid transfer protein （Zm-nsLTP） was cloned and expressed to investigate its CaM-binding activity. The cDNA of ZmnsLTP was amplified using RT-PCR （Fig. 1）, and then inserted into the vector pET32a（＋）. The recombinant vector pET-Zm-nsLTP was expressed in E.coli BL21 （DE3）trxB^-. Results of CaM-gel overlay assays （Fig.2） and CaM-sepharose pulldown experiments （Fig.3） indicated that recombinant Zm-nsLTP was bound to CaM in a Ca2＋-independent manner, which is in accordance with the way that CaMBP- 10 and Arabidopsis non-specific lipid transfer protein- 1 （At-nsLTP 1） are bound to CaM. The CaM-binding domain in Zm-nsLTP was mapped to the region of 47-60 amino acids （Fig. 3）, and online sequence analysis using Predict Protein program predicted that it has a BAA structure （Figs.4, 5）.

关 键 词：非特异性脂转移蛋白 钙调素 钙调素结合蛋白-10 钙调素结合结构域 

分 类 号：S513[农业科学—作物学] Q943.2[生物学—植物学]