Stable proteins may yield ’sweet’ biofuels

Scientists report they have developed a novel method of stabilizing proteins, including important enzymes used to produce certain artificial sweeteners and bioethanol.

The research will also be useful for extending the lifetime of therapeutic proteins employed to diagnose illnesses.

The team from the Polytechnic Institute of New York University inserted the unstable exoinulinase (EI) protein into a thermophilic scaffold protein, which is known for its stability and a propensity to protect less stable proteins.

The method stabilizes EI without compromising its enzymatic ability; in other words, its ability to act as a catalyst to enhance certain chemical reactions.  In the past, EI proteins lost their enzymatic activity too rapidly to be useful in turning the abundant plant sugar inulin into ultra-high fructose syrup or bioethanol.

The method can potentially be applied to a wide range of unstable proteins for therapeutic purposes, such as diagnosis of illnesses using proteins. The researchers have applied for a provisional patent.

Findings were published this month in the journal Protein Engineering, Design, and Selection.