کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1178295 | 962680 | 2013 | 7 صفحه PDF | دانلود رایگان |

The aim of this study was to elucidate the role of the two main mechanisms used to explain the stabilization of proteins by sugar glasses during drying and subsequent storage: the vitrification and the water replacement theory. Although in literature protein stability is often attributed to either vitrification or water replacement, both mechanisms could play a role and they should be considered simultaneously. A model protein, alkaline phosphatase, was incorporated in either inulin or trehalose by spray drying. To study the storage stability at different glass transition temperatures, a buffer which acts as a plasticizer, ammediol, was incorporated in the sugar glasses. At low glass transition temperatures (< 50 °C), the enzymatic activity of the protein strongly decreased during storage at 60 °C. Protein stability increased when the glass transition temperature was raised considerably above the storage temperature. This increased stability could be attributed to vitrification. A further increase of the glass transition temperature did not further improve stability. In conclusion, vitrification plays a dominant role in stabilization at glass transition temperatures up to 10 to 20 °C above storage temperature, depending on whether trehalose or inulin is used. On the other hand, the water replacement mechanism predominately determines stability at higher glass transition temperatures.
► Mechanisms for stabilization of a protein by sugar glasses are investigated.
► The two main mechanisms considered are vitrification and water replacement.
► Both mechanisms are distinguished by varying the glass transition temperature (Tg).
► Vitrification determined stability at Tg's up to 20 °C above storage temperature.
► Water replacement determined stability at Tg's well above storage temperature.
Journal: Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics - Volume 1834, Issue 4, April 2013, Pages 763–769