title: Highly stereoselective biosynthesis of (R)-α-hydroxy carboxylic acids through rationally re-designed mutation of D-lactate dehydrogenase.
abstract: An NAD-dependent D-lactate dehydrogenase (D-nLDH) of Lactobacillus bulgaricus ATCC 11842 was rationally re-designed for asymmetric reduction of a homologous series of α-keto carboxylic acids such as phenylpyruvic acid (PPA), α-ketobutyric acid, α-ketovaleric acid, β-hydroxypyruvate. Compared with wild-type D-nLDH, the Y52L mutant D-nLDH showed elevated activities toward unnatural substrates especially with large substitutes at C-3. By the biocatalysis combined with a formate dehydrogenase for in situ generation of NADH, the corresponding (R)-α-hydroxy carboxylic acids could be produced at high yields and highly optical purities. Taking the production of chiral (R)-phenyllactic acid (PLA) from PPA for example, 50 mM PPA was completely reduced to (R)-PLA in 90 min with a high yield of 99.0% and a highly optical purity (>99.9% e.e.) by the coupling system. The results presented in this work suggest a promising alternative for the production of chiral α-hydroxy carboxylic acids.
authors.affiliation: 1] State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, Shandong Province, People's Republic of China [2] College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China.
authors.forename: Zhaojuan
authors.initials: Z
authors.lastname: Zheng
authors.forename: Binbin
authors.initials: B
authors.lastname: Sheng
authors.forename: Chao
authors.initials: C
authors.lastname: Gao
authors.forename: Haiwei
authors.initials: H
authors.lastname: Zhang
authors.forename: Tong
authors.initials: T
authors.lastname: Qin
authors.forename: Cuiqing
authors.initials: C
authors.lastname: Ma
authors.forename: Ping
authors.initials: P
authors.lastname: Xu
mesh_terms: D055162:Biocatalysis; D002087:Butyrates / Q000378:metabolism; D002264:Carboxylic Acids / Q000378:metabolism*; D005560:Formate Dehydrogenases / Q000235:genetics / Q000378:metabolism; D045022:Lactate Dehydrogenases / Q000235:genetics* / Q000378:metabolism*; D007778:Lactobacillus / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics*; D009243:NAD / Q000235:genetics / Q000378:metabolism; D010667:Phenylpyruvic Acids / Q000378:metabolism; D011773:Pyruvates / Q000378:metabolism
chemical_list: D002087:Butyrates; D002264:Carboxylic Acids; D010667:Phenylpyruvic Acids; D011773:Pyruvates; D009243:NAD; C005087:alpha-ketobutyric acid; C012375:hydroxypyruvic acid; D045022:Lactate Dehydrogenases; C071195:D-lactate dehydrogenase; D005560:Formate Dehydrogenases; C031606:phenylpyruvic acid