Development of Dry-preservation Technology for Biological Protein at Room Temperature

－Measurements of Glass Transition Temperature and Residual Activity of Lactate Dehydrogenase－

抄録

The glass transition temperatures of the several kinds of materials which are considered to be effective as protective agents were measured before dry preservation experiment. The following four types of protective agents were selected to assess the dry-protective ability with Lactate Dehydrogenase (LDH); trehalose, trehalose with -Poly-L-Lysine (PLL) and trehalose with boron. The sample solutions of LDH with the various combinations of protective agents were rapidly vacuum-dried at the room temperature, followed by measuring their moisture content. After that, the dried samples were rehydration to measure the enzymatic activity by biochemical assay. The residual activity of LDH sample with trehalose was about 50% when its moisture content was 11 to 60 %. This dried-sample, however, suddenly lost its residual activity down to about 20 % when the moisture content decreased to 11 wt% or less. On the other hands, LDH samples with PLL alone and with trehalose + PLL kept their residual activities around 75 to 80 % in the wide range of moisture content. LDH samples with boron + trehalose kept their average residual activity from 69 to 74 %.