The long-term stability of recombinant (serine-17) human interferon-beta

Area of Science:

• Biochemistry
• Protein chemistry
• Immunology

Background:

• Interferon-beta (IFN-beta) is a crucial therapeutic protein.
• Ensuring the stability of recombinant protein preparations like HuIFN-beta SER is vital for reliable therapeutic and analytical applications.
• Formulation and storage conditions significantly impact protein stability.

Purpose of the Study:

• To evaluate the long-term stability of Escherichia coli-derived (Serine 17) human interferon-beta (HuIFN-beta SER) under various isothermal conditions.
• To identify degradation pathways and assess the impact of temperature on HuIFN-beta SER.
• To determine the suitability of HuIFN-beta SER as a stable reference standard.

Main Methods:

• Formulation of HuIFN-beta SER with SDS.
• Storage at multiple isothermal temperatures: -70°C, 4°C, 25°C, and 37°C.
• Stability assessment using three methods: bioassay (antiviral activity), SDS-PAGE (proteolytic cleavage and oligomerization), and RP-HPLC (purity and degradation products).

Main Results:

• HuIFN-beta SER showed no significant changes when stored for nearly one year at -70°C or 4°C.
• At elevated temperatures (25°C and 37°C), degradation was observed, including proteolytic cleavage, formation of noncovalent oligomers, and loss of antiviral activity.
• The formulation without carrier protein demonstrated stability under recommended frozen storage conditions.

Conclusions:

• Escherichia coli-derived HuIFN-beta SER is a stable protein preparation when stored at -70°C or 4°C.
• Elevated temperatures induce degradation, compromising its integrity and biological activity.
• This stable frozen reference preparation is suitable for use as a standard in bioassays and protein chemical analyses.