title: Use of a dual-origin temperature-controlled amplifiable replicon for optimization of human interleukin-1 beta synthesis in Escherichia coli.
abstract: A new dual-replicon recombinant plasmid, pPR53-tsr, has been constructed; it is a derivative of the expression vector pPR-TGATG-1 [Mashko et al., Gene 88 (1990) 121-126]. In contrast to its progenitor, pPR53-tsr is a low-copy-number (low-Cop) plasmid amplifiable in temperature-dependent fashion. In addition to both the replicon and the par locus from plasmid pSC101, providing segregational stability and a low Cop at 28 degrees C, the new plasmid contains a mutant ColE1 replicon whose RNAII is synthesized under the control of the pL promoter. The presence of a thermolabile repressor, cIts857, allows the thermo-inducible amplification of pPR53-tsr; the increased plasmid Cop is estimated at approx. 200 per genome 6 h after thermal induction at 42 degrees C. Thus, pPR53-tsr can be used as a donor of the thermo-inducible dual-replicon fragment for recombinant plasmids. Here, we employ such an approach for optimization of production of human interleukin-1 beta (hIL-1 beta) in Escherichia coli at a high level. The thermo-induced level of recombinant hIL-1 beta (re-hIL-1 beta) biosynthesis was around 9% of total cellular protein when the dual-replicon high-Cop vector was used. A method based on acidification of the water-soluble protein fraction to pH 4.0 has been developed that allows for the isolation of 80%-pure re-hIL-1 beta. The homogeneous material was obtained by two subsequent hydrophobic sorbent chromatographies. The protein yield ranged between 3-5 mg of re-hIL-1 beta/g of wet cells. The re-hIL-1 beta specific activity was about 2 x 10(8) units/mg, coinciding with that of the authentic hIL-1 beta.
authors.affiliation: All-Union Research Institute of Genetics and Selection of Industrial Microorganisms, Moscow, U.S.S.R.
authors.forename: S V
authors.initials: SV
authors.lastname: Mashko
authors.forename: A V
authors.initials: AV
authors.lastname: Mochulsky
authors.forename: S V
authors.initials: SV
authors.lastname: Kotenko
authors.forename: M I
authors.initials: MI
authors.lastname: Lebedeva
authors.forename: A L
authors.initials: AL
authors.lastname: Lapidus
authors.forename: N A
authors.initials: NA
authors.lastname: Mochulskaya
authors.forename: L S
authors.initials: LS
authors.lastname: Izotova
authors.forename: V P
authors.initials: VP
authors.lastname: Veiko
authors.forename: Y P
authors.initials: YP
authors.lastname: Vinetsky
authors.forename: S A
authors.initials: SA
authors.lastname: Ketlinsky
mesh_terms: D001483:Base Sequence; D003001:Cloning, Molecular; D004261:DNA Replication; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics*; D015870:Gene Expression; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012093:Replicon; D015183:Restriction Mapping; D013696:Temperature
chemical_list: D007375:Interleukin-1