摘要
Abstract
In order to enhance the stability and storage stability of NMN adenylyltransferase ( Nmnat) ,protective additives were added into the preparation of Nmnat, thereby expanding the scope of the use of enzymes. Some kinds of protective agents:solid alcohols (sorbitol, mannitol), sugar (sodium alginate, sucrose, mannose) and organic solvent (DMSO, propylene glycol-single ether, ethanol, glycerol) were investigated. The optimal combination additive (1. 5 g/L sorbitol, 1. 0 g/L alginate, 0. 5% DMSO) was obtained using the orthogonal experimental design. And the thermal stability, optimum reaction temperature, optimum reaction pH, the storage stability of Nmnat with combination additive were discussed. These additives might increase the optimal reaction temperature from 37 ℃ to about 50 ℃ due to their good protection effects, the activity increased by 24. 5% after preservation for 2 hours at 50 ℃, the range of pH stability from 7 . 0~8 . 0 expanded to 6 . 0~8 . 0 , the residual activity of Nmnat containing combination additive increased 15 . 65% after storing at 4 ℃ for 28 days.关键词
NMN转移酶/保护剂/热稳定性/正交实验Key words
Nmnat/protective agents/thermal stability/orthogonal experiment
