小麦返白系胆色素原脱氨酶纯化及编码cDNA序列分析  

Purification and Sequence Analysis of cDNA Coding Region for Porphobilinogen Deaminase from a Stage Albinism Line of Wheat

作　　者：程冬梅[1] 范三红[1] 刘香莉[1] 陈根云[2] 邓志勇[1] 郭蔼光[1] 

机构地区：[1]西北农林科技大学陕西省农业分子生物学重点实验室 [2]中国科学院上海植物生理生态研究所,上海200031

出　　处：《中国生物化学与分子生物学报》2006年第12期973-978,共6页Chinese Journal of Biochemistry and Molecular Biology

基　　金：国家自然科学基金项目(No.39570066);教育部博士点基金(No.1998071233)资助~~

摘　　要：以小麦(Triticumaestivum)返白系F772为材料,通过粗提、加热处理、硫酸铵分级沉淀和凝胶柱层析等方法,对胆色素原脱氨酶(PBGD)进行了提取纯化,纯化倍数为1092,得率为15%.纯化的PBGD约为37kD.对其部分生化性质的研究表明:高浓度的NH4+对酶活性有强烈的抑制,光照处理可以使酶活性降低.对纯化后的PBGDN末端氨基酸序列进行了测定.根据N端序列设计简并引物,获得了PBGD的cDNA全部编码区序列.它编码一个351个氨基酸的前体蛋白,有一个叶绿体导肽的序列.通过比较小麦PBGD与来自与其他物种的同源蛋白表明,有些氨基酸残基非常保守.Porphobilinogen deaminase （PBGD） was purified from F772, a mutant of ＇the stage albinism line of wheat＇, following the procedures including crude extracts, heat treatment, ammonium sulfate fraction and column chromatography. The enzyme was purified 1 092 fold with a special activity recovery of 15%. The wheat PBGD is a 37 kD protein. The activity of enzyme could be greatly inhibited by high contents of ammonium ion as well as lighting treatment. The N-terminal amino acid sequence was determined for PBGD, based on which, PBGD cDNA was obtained with the degenerate primers. Sequence analysis of coding region of PBGD indicated that it encodes a precursor of 351 residues with a typical chloroplast-targeted peptide. In comparison of wheat PBGD and its homologs from other species, it was found that there are some highly conserved amino acid residues among these proteins.

关 键 词：小麦返白系 胆色素原脱氨酶 N末端氨基酸测序 纯化 CDNA克隆 

分 类 号：Q946[生物学—植物学]