文献类型：期刊文献

英文题名：Efficient synthesis of a statin precursor in high space-time yield by a new aldehyde-tolerant aldolase identified from Lactobacillus brevis

作者：Jiao, Xue-Cheng[1];Pan, Jiang;Xu, Guo-Chao;Kong, Xu-Dong;Chen, Qi;Zhang, Zhi-Jun;Xu, Jian-He

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China; E China Univ Sci & Technol, Shanghai Collaborat Innovat Ctr Biomfg, Shanghai 200237, Peoples R China

年份：2015

卷号：5

期号：8

起止页码：4048

外文期刊名：CATALYSIS SCIENCE & TECHNOLOGY

收录：;EI(收录号：20153001065661);WOS:【SCI-EXPANDED(收录号:WOS:000358237400021)】；

基金：This work was financially supported by the National Natural Science Foundation of China (no. 21276082) and Ministry of Science and Technology, PR China (no. 2011CB710800 & 2011AA02A210).

语种：英文

外文关键词：Crystal structure - Stereochemistry - Acetaldehyde - Hydrogen bonds - Ketones - Stability - Substrates

摘要：A novel 2-deoxyribose-5-phosphate aldolase (LbDERA) was identified from Lactobacillus brevis, with high activity, excellent thermostability and high tolerance against aldehyde substrates. The half-lives of LbDERA incubated in 300 mM acetaldehyde and chloroacetaldehyde were 37.3 and 198 min, respectively, which are 2- and 7-fold higher than those of EcDERA from Escherichia coli. The crystal structure of LbDERA determined at 1.95 angstrom resolution revealed a stable quaternary structure which might account for its excellent aldehyde tolerance. A single mutation, E78K, was introduced to LbDERA through a consensus sequence approach, resulting in significant improvements of both thermostability and aldehyde tolerance. According to the crystal structure of LbDERA(E78K), two additional hydrogen bonds and one salt bridge were introduced compared with wild-type LbDERA. As a result of its high substrate tolerance, LbDERA(E78K) could efficiently catalyze a sequential aldol condensation with 0.7 M chloroacetaldehyde and 1.4 M acetaldehyde, affording a key chiral precursor of statins, (3R,5S)-6-chloro-2,4,6-trideoxyhexapyranoside, with an unprecedented space-time yield of 792.5 g L-1 d(-1) and only 2.5 g L-1 of catalyst loading.