TY - JOUR AU - Yen, Hoang Thi Thu AU - Lan, Vu Thi AU - Thu Hue, Huynh Thi PY - 2020/03/19 Y2 - 2024/03/29 TI - Expression of gene encoding flavonol synthase isolating from trung du xanh tea (Camellia sinensis var. macrophylla) in E. coli JF - Academia Journal of Biology JA - AJB VL - 42 IS - 1 SE - Articles DO - 10.15625/0866-7160/v42n1.13833 UR - https://vjs.ac.vn/index.php/vjbio/article/view/13833 SP - AB - <p>Common flavonols in plants including quercetin, kaempferol and myricetin are synthesized from dihydroflavonols (dihydroquercetin-DHQ, dihydrokaempferol-DHK and dihydromyricetin-DHM) by flavonol synthase (FLS). In tea, FLS has been shown to metabolize dihydroquercetin to quercetin. The FLS gene was cloned and sequenced from the cultivated tea (<em>Camellia sinensis</em><em> </em>var. <em>macrophylla</em>) in Thai Nguyen province. In this study, we presented the results of optimizing and designing an expression vector for recombinant FLS (recombinant FLS-rFLS). The FLS gene was ligated completely to the pET32a (+) vector, then expressed in <em>E. coli </em>Rosetta1 and Rosetta2 strain. Using 1mM IPTG to induce the expression of rFLS at 37<sup>o</sup>C, rFLS was obtained with 52.83 kDa in size and existed predominantly as insoluble form. <em>E. coli</em> Rosetta1 pET32a (+)<sub>_</sub><em>FLS</em>produces rFLS in the soluble fraction than <em>E. coli</em> Rosetta2 pET32a (+)<sub>_</sub><em>FLS</em>. Next, <em>E. coli</em> Rosetta1 pET32a (+)<sub>_</sub><em>FLS</em>was optimized for expression at temperatures of 30<sup>o</sup>C, 23<sup>o</sup>C and 16<sup>o</sup>C (24 and 48 hours). After being induced for expression with 1mM IPTG in 48 hours and cultured at 16<sup>o</sup>C, <em>E. coli</em> Rosetta1 strain containing pET32a (+) <em>FLS</em> produced the largest amount of rFLS in the soluble form.</p><p> </p> ER -