Pantoea agglomerans phenylalanine aminomutase (PaPAM) catalyzes the conversion of α-phenylalanine to more valuable (S)-β-phenylalanine. However, its low enzyme activity and poor thermal stability limit its industrial application. In order to improve its thermostability and enzyme activity, this study reduced the flexibility of loops above the active center of PaPAM by mutating amino acids on the loops and amino acids at the interaction site to stabilize the active center structure. A mutant I91M with significantly improved thermostability was screened, which had 83% residual enzyme activity after incubating at 50 ℃ for 1 h, while the activity of wild-type enzyme only had 30% remained. These results are helpful for further studies and industrial applications of PaPAM.
LIU Hui
,
ZHANG Weimiao
,
XU Jian
,
ZHOU Li
,
ZHOU Zhemin
. Thermostability modification of Pantoea agglomerans phenylalanine aminomutase[J]. Food and Fermentation Industries, 2019
, 45(13)
: 59
-64
.
DOI: 10.13995/j.cnki.11-1802/ts.019924
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