Transketolase variants with increased thermostability have been obtained by engineering cofactor-binding loops towards those found in a thermophilic homologue.

Thermal annealing behaviour is enhanced by mutations in one loop, and abolished by mutations in the second loop.

One thermostabilising mutation, H192P, also doubled the specific activity at 25 °C.

The thermostabilising mutant, H192P, was also more active than wild-type transketolase, in reactions at elevated temperatures.

The variants confirmed the key role of the cofactor-binding loops in transketolase aggregation at elevated temperatures.