Co-Solvents Effects on the Stability of Recombinant Immunotoxin Denileukin Diftitox: Structure and Function Assessment

Autor: Mehdi Zeinoddini, M. A. Nasiri Khalili, Sh. Bayat, Azadeh Azizi
Rok vydání: 2019
Předmět:
Zdroj: Iranian Journal of Science and Technology, Transactions A: Science. 43:2091-2097
ISSN: 2364-1819
1028-6276
Popis: Denileukin diftitox (brand name: Ontak, DAB389IL2) is the first recombinant immunotoxin approved by FDA for treatment of CTCL (cutaneous T cell lymphoma). This smart toxin is contains truncated diphtheria toxin (DT387), genetically fused to human interleukin 2 (IL2). Like other pharmaceutical productions, there is an aggregation problem in this fusion protein production and achieving a stable protein structure is mainly recommended for clinical use. Herein, we have investigated the effects of co-solvents on the structure and function of denileukin diftitox. In this work, the histidine-tagged DAB389IL2 was expressed in Escherichia coli and after solubilizing and refolding, the inclusion body was purified using nickel chelate affinity chromatography. Then, the structural alterations of the refolded protein in the presence of different co-solvents (sorbitol, trehalose, and sucrose) were investigated using fluorescence and circular dichroism (CD) techniques. Moreover, the nuclease activity of the refolded protein was traced to confirm the refolding process,. Finally, the biological activity of produced DAB389IL2 was carried out using MTT assay. The results revealed that, DAB389IL2 is more stable in PBS including sorbitol (30 mM) than other stabilizers. The tryptophan residues flexibility—exposure of DAB389IL2 to the solvent, in the presence of sorbitol, with respect to fluorescence quenching by acrylamide, indicated the best characterization. Also, in the presence of 2 ng/ml of protease, DAB389IL2 was completely undigested and so it indicated the highly stability of the fusion protein to proteases. Furthermore, the refolding and function of the produced fusion protein is verified by DNase activity and bioassay. Therefore, the data of this research could give further insights into the protein refolding mechanism and formulation of the protein in the presence of co-solvents.
Databáze: OpenAIRE
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