Semi-rational molecular engineering to improve stereoselectivity of L-rhamnulose-1-phosphate aldolase for D-psicose synthesis

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  • (Key Laboratory of Carbohydrate Chemistry & Biotechnology Ministry of Education, Jiangnan University, Wuxi 214122, China)

Online published: 2018-08-30

Abstract

Rare sugars D-psicose shows great potentials in many field, such as food, pharmaceutical and medicinal industries. However, large scale synthesis of D-psicose with a high yield still remains a challenge. In our previous study, DHAP-dependent aldolase L-rhamnulose-1-phosphate aldolase (RhaD) from Escherichia coli lost its stereoselectivity when accepting D-glyceraldehyde as the acceptor. As a result, two rare sugars D-psicose and D-sorbose were generated with a ratio of 1∶1. In order to optimize the stereoselectivity of RhaD to exclusively produce D-psicose, site-saturation mutagenesis of tyrosine 152 of RhaD with other nineteen amino acids were performed. The results showed that D-psicose was favored by RhaD Y152A mutant and the ratio was increased eight folds. This study will provide theoretical foundation for further molecular modification of RhaD for the synthesis of D-psicose as a single product.

Cite this article

WANG Ma-yan et al . Semi-rational molecular engineering to improve stereoselectivity of L-rhamnulose-1-phosphate aldolase for D-psicose synthesis[J]. Food and Fermentation Industries, 2018 , 44(7) : 1 -7 . DOI: 10.13995/j.cnki.11-1802/ts.016748

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