Trehalose and sorbitol alter the kinetic pattern of inactivation of glutamate dehydrogenase during drying in levitated microdroplets.
Trehalose and sorbitol alter the kinetic pattern of inactivation of glutamate dehydrogenase during drying in levitated microdroplets.
复制标题
海藻糖和山梨醇改变悬浮微滴干燥过程中谷氨酸脱氢酶失活的动力学模式。
DOI：
10.1002/jps.23743
复制
发表时间：
2013
影响因子：
3.8
通讯作者：
Geoffrey Lee
中科院分区：
文献类型：
--
作者：
E. Lorenzen;Geoffrey Lee
单液滴声悬浮器用于测定在添加海藻糖或山梨醇的存在下谷氨酸脱氢酶的干燥速率和失活动力学。还在台式机器上在干燥气体温度的相同工艺条件下对溶液进行喷雾干燥。海藻糖和山梨糖醇都延迟了酶失活的开始点，该点位于干燥临界点之后。这两种碳水化合物也降低了在随后的灭活阶段计算的表观灭活速率常数。因此，碳水化合物在液滴干燥期间稳定酶，并且主要在降速干燥期间稳定颗粒形成。当作为悬浮的单液滴检查时，两种碳水化合物的稳定作用之间没有差异。这表明水置换作为悬浮液滴/颗粒中的稳定机制的重要性。在喷雾干燥时，在60°C的干燥气体（出口）温度下，海藻糖比山梨糖醇更能稳定酶。这表明在喷雾干燥器中小雾化液滴的快速干燥过程中，海藻糖而非山梨糖醇形成玻璃。
A single-droplet acoustic levitator was used to determine the drying rate and the kinetics of inactivation of glutamate dehydrogenase in the presence of added trehalose or sorbitol. The solution was also spray dried under the same process condition of drying gas temperature on a bench-top machine. Both trehalose and sorbitol delay the point of onset of enzyme inactivation which lies after the critical point of drying. Both carbohydrates also reduce the apparent rate constant of inactivation calculated during the subsequent inactivation phase. The carbohydrates stabilise, therefore, the enzyme during droplet drying and particle formation mainly during the falling rate drying period. There is no difference between the stabilising effects of the two carbohydrates when examined as levitated single droplets. This suggests the importance of water replacement as a stabilising mechanism in the levitated droplets/particles. On spray drying, the trehalose stabilises the enzyme better than does the sorbitol at a drying gas (outlet) temperature of 60°C. This suggests glass formation with the trehalose but not the sorbitol during the very rapid drying process of small-atomised droplets in the spray dryer.