Altering the Regioselectivity of a Nitroreductase in the Synthesis of Arylhydroxylamines by Structure-Based Engineering

作者：Bai, Jing; Zhou, Yong; Chen, Qi; Yang, Qing; Yang, Jun^*

来源：ChemBioChem, 2015, 16(8): 1219-1225.

DOI：10.1002/cbic.201500070

• arylhydroxylamines
• enzyme catalysis
• nitroreductases
• protein engineering
• regioselectivity

Nitroreductases have great potential for the highly efficient reduction of aryl nitro compounds to arylhydroxylamines. However, regioselective reduction of the desired nitro group in polynitroarenes is still a challenge. Here, we describe the structure-based engineering of Escherichia coli nitroreductase NfsB to alter its regioselectivity, in order to achieve reduction of a target nitro group. When 2,4-dinitrotoluene was used as the substrate, the wild-type enzyme regioselectively reduced the 4-NO2 group, but the T41L/N71S/F124W mutant primarily reduced the 2-NO2 group, without loss of activity. The crystal structure of T41L/N71S/F124W and docking experiments indicated that the regioselectivity change (from 4-NO2 to 2-NO2) might result from the increased hydrophobicity of residues 41 and 124 (proximal to FMN) and conformational changes in residues 70 and 124.

• 出版日期2015-5-26
• 单位大连理工大学