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Applicability of New Expression Vectors for Both Engineering Uses and Biological Studies
Author(s) -
Chao YunPeng,
Chiang ChungJen,
Wang YuLing,
Wang Zei Wen
Publication year - 2003
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1021/bp0300016
Subject(s) - lac operon , plasmid , clone (java method) , gene , biology , lac repressor , cloning (programming) , expression vector , gene expression , genetics , promoter , microbiology and biotechnology , recombinant dna , computer science , programming language
To be applicable for both engineering and biological uses, the plasmid with the features of tight regulation, high‐level expression, and subtle modulation (or homogeneous induction) is required. IPTG‐inducible promoters are of particular interest since they acquire the latter two merits but usually lack stringency. To this end, two plamids have been developed to contain the T7 A1 promoter along with either lacI q or lacI gene. As a production system, the cells harboring the plamids with the lacZ gene clone enabled production of the maximal protein accounting for 35% total cell content upon induction by a saturating IPTG level. This protein yield is amplified over 700‐fold relative to that at the uninduced state. As a system for biological study, the ppc negative strain bearing the plasmid with the ppc gene clone failed to grow on glucose without IPTG induction but immediately resumed its growth in the presence of IPTG. Moreover, the level of the ppc gene product in the cell was varied by various IPTG, and the result revealed that the wild‐type ppc level was sufficient to support the saturated growth of the cell on glucose. Overall, it illustrates the applicability of these plasmids to needs in the post‐genome era.