Cloning And Expression Of Human Interleukin 18 And Its Mutant HIL18-Ile48Met

In this thesis, human interleukin-18(hIL-18) and its mutant hIL18-Ile48Met were cloned and expressed, respectively. The mature hIL-18 gene was obtained by Polymerase Chain Reation(PCR) using pre-hIL-18 DNA fragment as a templete , which was cloned from human peripheral blood monocyte(PBMC) by RT-PCR.A recombinant gene pKKH-hIL-18, was constructed and was transformed into E.coli DH5α. IPTG(iso-propyl-β-D-thiogalactoside) induced expression amount of the recombinant hIL-18 was up to 20% of the total proteins of E.coli DH5α. A hIL-18 mutant, in which Ile48 was mutated into Met,was produced by Overlap PCR. A recombinant pBV220-hIL18-Ile48Met was constructed and transformed into DH5(.The protein expression of the mutant hIL18-Ile48Met which was induced with different degree of temperature , was observed as a band about 18 KD on SDS-PAGE, and its amount was up to 25% of the total proteins.