title: Recombinant expression, different downstream processing of the disulfide-rich anti-tumor peptide Ranpirnase and its effect on the growth of human glioma cell line SHG-44.
abstract: Ranpirnase (Onconase) is a frogspawn-derived disulfide-rich peptide with ribonuclease activity that may be used for tumor treatment. In the present study, we established an efficient approach for preparing mature ranpirnase which may be used for research and therapeutic purposes. The designed ranpirnase precursors carried a 6xHis-tag and were recombinantly expressed inEscherichia coli. After S-sulfonation, the precursors were purified by immobilized metal-ion affinity chromatography. Following removal of the tag by aminopeptidase cleavage, cyclization andin vitrooxidative refolding, the mature ranpirnase was obtained with considerable yield, and the yield of mature ranpirnase was ~50-60 mg per liter cultures. In addition, ranpirnase inhibited the growth of human glioma cells SHG-44 in a dose-dependent manner. Thus the present study has provided an efficient approach for the preparation of active ranpirnase and its analogues for future studies.
authors.affiliation: Institute of Protein Research, College of Life Sciences and Technology, Tongji University, Shanghai 200092, P.R. China.
authors.forename: Xiao-Min
authors.initials: XM
authors.lastname: Wang
authors.affiliation: Institute of Protein Research, College of Life Sciences and Technology, Tongji University, Shanghai 200092, P.R. China.
authors.forename: Zhan-Yun
authors.initials: ZY
authors.lastname: Guo
keywords: cyclotransferase; disulfides; purification; ranpirnase; recombinant expression; refolding