Molecular Characterization of Mungbean (Vigna radiata L.) Starch Branching Enzyme I

作者：Chang Jia Wei; Li Sing Chung; Shih Yun Chi; Wang Reuben; Chung Pei Shan; Ko Yuan Tih^*

来源：Journal of Agricultural and Food Chemistry, 2010, 58(19): 10437-10444.

DOI：10.1021/jf102129f

• Mungbean
• starch branching enzyme
• gene expression
• recombinant enzyme

Mungbean (Vigna radiata L. cv. Tainan no. 5) starch branching enzyme I (SBE, EC 2.4.1.18) cDNA, Vrsbel, was cloned, and its expression was characterized. Conserved regions of the family B SBE were used to amplify a full length cDNA of 2208 bp. Phylogeny was analyzed, and the partial 3D structure and functional features were predicted. Catalytic residues were identified in the (alpha/beta)(8)-fold, and a unique loop from F365 to F376 between beta 3/alpha 3 was located. Gene expression of Vrsbel in seeds during growth showed that the transcript appeared from week 1 and increased substantially at week 3-4. It was cloned into the pET30 vector and expressed in E. coli BL21(DE3) pLysS cells as a soluble recombinant protein. The affinity-purified recombinant VrSBEI exhibited a specific activity of 314.6 U/mg as an active enzyme with 114-fold activity enrichment from the crude extract.

• 出版日期2010-10-13
• 单位中国医科大学