Construction of the mutants of rice nonspecific lipid transfer protein and expression comparison in two kinds of thioredoxin fusion expression vectors

• Published in: Shengwu gongcheng xuebao Vol. 18; no. 2; p. 167
• Main Authors: Ge, Xiao-Chun, Chen, Ji-Chao, Wang, Wen-Yi, Cao, Kai-Ming, Sun, Chong-Rong
• Format: Journal Article
• Language: Chinese
• Published: China 01.01.2002
• Subjects: Amino Acid Sequence; Carrier Proteins - genetics; Carrier Proteins - isolation & purification; Carrier Proteins - metabolism; Gene Expression; Genetic Engineering; Genetic Vectors; Molecular Sequence Data; Mutagenesis, Site-Directed; Oryza - genetics; Plant Proteins - genetics; Plant Proteins - isolation & purification; Plant Proteins - metabolism; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - isolation & purification; Recombinant Fusion Proteins - metabolism; Thioredoxins - genetics
• ISSN: 1000-3061

Five structural important residues of rice nonspecific lipid transfer protein LTP110 were mutated by site-directed mutagenesis. Sequence results showed that they were all mutated successfully. After trying various E. coli expression systems, thioredoxin fusion expression system was found to be a proper system to express wild type and mutant LTP110. cDNA sequences encoding wild type LTP110 and the mutants Y17A, P72L, R46A, D43A, C50A were cloned into two kinds of thioredoxin fusion expression vectors. The expression results were compared. In pTrxFus/GI724 expression system, wild type LTP110 and the mutants Y17A, P72L, R46A could be expressed at low level while D43A and C50A could not be expressed normally; in pET32a(+)/BL21 (DE3) trxB- expression system, wild type LTP110 and all mutant proteins could be expressed very well and the levels were higher than that in pTrxFus/GI724 system. LTP110 fusion protein expressed in pET32a(+) vector was purified and its activity was checked by fluorescence labeled fatty acid