Premium
DSC Confirmation That Vitrification Is Not Necessary for Stabilization of the Restriction Enzyme Eco RI Dried with Saccharides
Author(s) -
Buera María P.,
Rossi Silvia,
Moreno Silvia,
Chirife Jorge
Publication year - 1999
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1021/bp990032u
Subject(s) - differential scanning calorimetry , raffinose , ecori , glass transition , trehalose , vitrification , chemistry , glycerol , chromatography , plasticizer , sucrose , enzyme , food science , biochemistry , restriction enzyme , organic chemistry , polymer , thermodynamics , medicine , dna , physics , andrology
The glass transition temperature ( T g ) of preparations of the restriction enzyme Eco RI, vacuum‐dried in the presence of sucrose, trehalose, or raffinose, was determined using differential scanning calorimetry. T g values were well below those expected for low‐moisture sucrose, trehalose, or raffinose, and this was attributed to the presence of glycerol (a plasticizer), which was a main component of the restriction enzyme preparation. This was verified by determining the glass transition temperature of glycerol, which was found to be (onset value) −77 °C. Present results confirmed that vitrification (i.e., glass formation) was not necessary for enzyme protection in present low‐moisture saccharide systems. As shown in previous work, enzyme Eco RI was very stable stored at 37/45 °C in spite of the fact that sugar matrices were completely rubbery, as unequivocally demonstrated in the present work.