Production of a biologically active human interleukin 18 requires its prior synthesis as pro-IL-18
Production of a biologically active human interleukin 18 requires its prior synthesis as pro-IL-18
复制标题
DOI:
10.1006/cyto.2000.0749
复制
发表时间:
2000-10-01
期刊:
影响因子:
3.8
通讯作者:
Rubinstein, M
中科院分区:
文献类型:
--
作者:
Liu, BL;Novick, D;Rubinstein, M
Interleukin (IL-)18 is an activator of NK cells and a co-inducer of Th-1 cytokines, sharing structural features with the IL-1 family of proteins. Unlike most other cytokines, IL-18 and IL-1 beta lack a signal peptide, have an all beta -pleated sheet structure and are synthesized as biologically inactive precursors (pro-IL-18 and pro-IL-1 beta), These precursors are cleaved by caspase-1 (IL-1 beta -converting enzyme, ICE) to form the biologically active mature cytokines, Direct expression of mature recombinant human IL-18 in E, coli resulted in a partially active cytokine, We tested the possibility that correct folding of huIL-18 requires its prior synthesis as pro-IL-18, Because caspase-1 is not readily available, we constructed an expression vector encoding human pro-IL-18 in which the caspase-1 cleavage site was mutated into a factor Xa site. To facilitate purification, the mutated pro-IL-18 cDNA was fused in frame to a glutathione-S-transferase (GST) coding sequence. The GST-pro-IL-18 fusion protein was expressed in E, coli, captured on glutathione agarose and mature human IL-18, exhibiting high biological activity was released upon cleavage with factor Xa, This result indicates that correct folding of huIL-18 occurs at the level of pro-IL-18 and provides a practical way to produce biologically active huIL-18, (C) 2000 Academic Press.