您好,欢迎访问中国热带农业科学院 机构知识库!

Characterization of a root-specific beta-thioglucoside glucohydrolase gene in Carica papaya and its recombinant protein expressed in Pichia pastoris

文献类型: 外文期刊

作者: Wang, Meng 1 ; Li, Dingqin 1 ; Sun, Xuepiao 1 ; Zhu, Yun Judy 2 ; Nong, Han 1 ; Zhang, Jiaming 1 ;

作者机构: 1.CATAS, MOA Key Biotechnol Lab Trop Crops, Inst Trop Biosci & Biotechnol, Haikou 571101, Hainan Province, Peoples R China

2.Hawaii Agr Res Ctr, Aiea, HI USA

3.Hainan Univ, Coll Agr, Haikou 571101, Hainan Province, Peoples R China

关键词: beta-Thioglucoside glucohydrolase;Carica papaya;CpTGG2;Enzyme kinetics;Recombinant protein

期刊名称:PLANT SCIENCE ( 影响因子:4.729; 五年影响因子:5.132 )

ISSN: 0168-9452

年卷期: 2009 年 177 卷 6 期

页码:

收录情况: SCI

摘要: Plant P-thioglucoside glucohydrolases (TGGs or myrosinases) are a young class of enzymes in the glycosyl hydrolase family 1 and have a narrow distribution. TGG genes have mainly been cloned from crucifers, while TGGs in other species have received little attention. The TGG gene CpTGG2 and its recombinant protein from papaya were characterized in this paper. This is the first plant TGG gene without unusual intron splicing borders, as present in all other available TGG genes. Phylogenetic analysis indicated that plant myrosinases are divided into two major lineages. CpTGG2 is located in the lineage constituted by AtTGG4-6 from Arabidopsis thaliana, while the rest of myrosinases (including MA, MB and MC subfamilies) are grouped into another lineage. RT-PCR analysis indicated that CpTGG2 was specifically expressed in the root. The recombinant CpTGG2 expressed in yeast had a subunit mass of 70 kDa, and had low basal TGG activity without addition of ascorbate. Low concentrations of ascorbate stimulated CpTGG2 activity, while high concentrations were inhibitory. CpTGG2 was active in broad pH and temperature ranges, similar to AtTGG4 and AtTGG5. The apparent K(m) and V(max) were 2.24 mM and 24.3 mu mol min(-1) mg(-1) when sinigrin was the substrate. The calculated k(cat)/K(m) value was 1.3 x 10(4) S(-1) M(-1) Our results reshaped and expanded the myrosinase family structure and provided clues to the evolution of myrosinase genes. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

  • 相关文献

[1]Production of triploid plants of papaya by endosperm culture. Sun, De-Quan,Lu, Xin-Hua,Mo, Yi-Wei,Xie, Jiang-Hui,Liang, Guo-Lu,Guo, Qi-Gao.

作者其他论文 更多>>