Recombinant interferon-β1b (IFN-β1b) is an effective remedy against multiple sclerosis and other diseases. However, use of small polypeptide (molecular weight is around 18.5 kDa) is limited due to poor solubility, stability, and short half-life in systemic circulation. To solve this problem, we constructed two variants of PASylated IFN-β1b, with PAS sequence at C- or N-terminus of IFN-β1b. The PAS-modified proteins demonstrated 4-fold increase in hydrodynamic volume of the molecule combined with 2-fold increase of in vitro biological activity, as well as advanced stability and solubility of the protein in solution as opposed to unmodified IFN-β1b. Our results demonstrate that PASylation has a positive impact on stability, solubility, and functional activity of IFN-β1b and potentially might improve pharmacokinetic properties of the molecule as a therapeutic agent.

No abstract