Non-equivalence of D- and L-trehalose in stabilising alkaline phosphatase against freeze-drying and thermal stress. Is chiral recognition involved?

Comparison of the ability of the enantiomeric forms of trehalose to stabilise alkaline phosphatase towards dehydration and heat showed that natural D-trehalose is superior to L-trehalose, although both disaccharides provide some protection for the enzyme. The result of this novel experiment suggests a chiral differentiation between carbohydrate and protein and thus lends support for the water replacement hypothesis of solute-based stabilisation of biomolecules, but the non-crystallinity and the physical form of the L-isomer may also be a key factor.