Effects of various cyclodextrins on the stability of freeze‐dried lactate dehydrogenase

The effects of eight cyclodextrins (CDs) on the stability of freeze‐dried lactate dehydrogenase (LDH) were investigated. Five low‐molecular weight saccharides were used as a reference. In the samples without saccharides, LDH activity was decreased by freeze‐drying. The LDH activities of the samples with 2‐hydroxypropylated CDs (HP‐CDs) such as 2‐hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) showed only a small decrease and were more effective protein stabilizers than low‐molecular weight saccharides. HP‐β‐CD more effectively stabilized LDH than trehalose, at a sugar concentration of less than 1.0 w/w% and furthermore, a close relationship existed between the highly stabilizing effect and the degree of substitution of polar substituents. © 2007 Wiley‐Liss, Inc. 96: 3140-3143, 2007