Hydroxynitrile lyases stability

Examples of LLC phases for enzyme stabilization and bio catalysis include the micellar and LLC phases water (or glucose in water)/oclanol/octyl-/3-D-glucoside LLC system for accelerating /3-D-glucosidase-calalyzed hydrolysis of octyl-/ -n-glucoside to form glucose and octanol [108] and the use of LLC phases of numerous commercial surfactants to accelerate the (S)-hydroxynitrile lyase-catalyzed synthesis of (S)-mandelonitrile [109]. 

Promising results using hydroxynitrile lyases were achieved by Gaisberger et al. and Lou et al. in tetrafluoroborate-based ionic liquids, especially when using the enzyme from Prunus amygdalus. Gaisberger et al. used the lyases for reactions with long chain aldehydes. Lou et al. discovered increased thermal enzyme stability, improved enantioselectivity and enzymatic activity for a transcyanation reaction at low ionic liquid contents in buffer solution [52,53]... 

Bauer, M., Griengl, H., and Steiner, W. (1999) Parameters influencing stability and activity of a S-hydroxynitrile lyase from Hevea brasiliensis in two-phase systems. Enzyme Microb. Technol., 24, 514-522. 

With the use of bio catalysts, the preparation of chiral cyanohydrins is possible. (R)- as well as (S)-cyanohydrins are now easily available as a result of the excellent accessibility, the relatively high level of stability and the easy handling of hydroxynitrile lyases (HNLs). An example of the synthesis of (S)-cyanohydrins is shown in Fig. 10.40. The optimization of reaction conditions (solvent, temperature and site-directed mutagenesis) has enabled HNL-catalyzed preparation of optically active cyanohydrins on an industrial scale. 

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