Background: Although the stability of proteins is of significance to maintain protein function
for therapeutical applications, this remains a challenge. Herein, a general method of preserving
protein stability and function was developed using gelatin films.
Methods: Enzymes immobilized onto films composed of gelatin and Ethylene Glycol (EG) were developed
to study their ability to stabilize proteins. As a model functional protein, β-glucosidase was selected.
The tensile properties, microstructure, and crystallization behavior of the gelatin films were assessed.
Results: Our results indicated that film configurations can preserve the activity of β-glucosidase under
rigorous conditions (75% relative humidity and 37°C for 47 days). In both control films and films containing
1.8 % β-glucosidase, tensile strength increased with increased EG content, whilst the elongation
at break increased initially, then decreased over time. The presence of β-glucosidase had a negligible
influence on tensile strength and elongation at break. Scanning electron-microscopy (SEM) revealed
that with increasing EG content or decreasing enzyme concentrations, a denser microstructure
Conclusion: In conclusion, the dry film is a promising candidate to maintain protein stabilization and
handling. The configuration is convenient and cheap, and thus applicable to protein storage and transportation
processes in the future.