Cloning, sequence analysis, and prokaryotic expression of LaF3H gene from Lepidium apetalum / 中草药

ABSTRACT

Objective In order to study the key genes involved in flavonoid biosynthesis pathway, the flavanone-3-hydroxylase (F3H) gene was isolated from Lepidium apetalum, which is named as LaF3H. Meanwhile, the sequence analysis, prokaryotic expression, and purification were also performed. Methods Specific primers were designed according to LaF3H gene sequences in the transcriptome data of L. apetalum, and the cDNA sequence of LaF3H gene was isolated from L. apetalum. By construction the prokaryotic expression vector pET-32a-LaF3H, the recombinant LaF3H protein was expressed in Escherichia coli BL21 (DE3) cells under IPTG induction. Results The open reading frame (ORF) of LaF3H was 1 080 bp, which encoded a protein of 359 amino acid residues, with a predicted molecular mass of 40 320. Sequence analysis showed that LaF3H contains five conserved motifs of F3H protein. The phylogenetic analysis indicated that LaF3H protein showed the highest homology with F3H protein from cruciferous plants (such as AtF3H from Arabidopsis thaliana). The prokaryotic expression vector pET-32a-LaF3H was constructed and the recombinant LaF3H protein was successfully expressed in E. coli BL21 (DE3) cells. Furthermore, the recombinant LaF3H protein was purified through Ni2+ affinity chromatography. Conclusion The LaF3H gene was isolated from L. apetalum and the recombinant LaF3H protein was obtained. The results of this study provided the foundation for the further preparation of LaF3H antibody and detection of LaF3H enzyme activity, and were helpful for functional characterization of LaF3H gene involved in flavonoid biosynthesis pathway of L. apetalum.