title: Enzymatic preparation of optically pure (+)-2-azabicyclo[2.2.1]hept-5-en-3-one by (-)-γ-lactamase from Bradyrhizobium japonicum USDA 6.
abstract: Whole cells of Bradyrhizobium japonicum USDA 6 showed both (+)-γ-lactamase activity and (-)-γ-lactamase activity. Insight into the genome of B. japonicum USDA 6 revealed two potential γ-lactamases: a type I (+)-γ-lactamase and a (-)-γ-lactamase, making it the first strain to contain two totally different enantioselective lactamases. Both recombinant enzymes could easily be used to prepare either optically pure (+)-γ-lactam ((+)-2-azabicyclo[2.2.1]hept-5-en-3-one) or optically pure (-)-γ-lactam ((-)-2-azabicyclo[2.2.1]hept-5-en-3-one), which are versatile synthetic building blocks for the synthesis of various carbocyclic nucleosides and carbocyclic sugar analogues. Bioinformatic analysis showed that the type I (+)-γ-lactamase belongs to the amidase signature family, with 504 amino acids; the (-)-γ-lactamase, which consists of 274 amino acids, belongs to the hydrolase family. Here, we report that B. japonicum USDA contains a (-)-γ-lactamase in addition to a (+)-γ-lactamase, and it is the (-)-γ-lactamase from this strain that is examined in detail in this Letter. Enzymatic synthesis of optically pure (+)-γ-lactam with nearly 50% isolated yield and >99% ee was achieved.
authors.affiliation: State Key Laboratory of Chemical Resources Engineering, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.
authors.forename: Shaozhou
authors.initials: S
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Chemical Resources Engineering, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.
authors.forename: Lu
authors.initials: L
authors.lastname: Ren
authors.affiliation: State Key Laboratory of Chemical Resources Engineering, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.
authors.forename: Songzhu
authors.initials: S
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Chemical Resources Engineering, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.
authors.forename: Cuiyu
authors.initials: C
authors.lastname: Gong
authors.affiliation: State Key Laboratory of Chemical Resources Engineering, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.
authors.forename: Dawei
authors.initials: D
authors.lastname: Song
authors.affiliation: State Key Laboratory of Chemical Resources Engineering, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China. Electronic address: zhenggj@mail.buct.edu.cn.
authors.forename: Guojun
authors.initials: G
authors.lastname: Zheng
mesh_terms: D000581:Amidohydrolases / Q000378:metabolism*; D020369:Bradyrhizobium / Q000166:cytology / Q000201:enzymology*; D007769:Lactams / Q000737:chemistry / Q000378:metabolism*; D015394:Molecular Structure; D013237:Stereoisomerism; D014481:United States; D016885:United States Department of Agriculture
chemical_list: D007769:Lactams; C062350:2-azabicyclo(2.2.1)hept-5-en-3-one; D000581:Amidohydrolases; C401943:gamma-lactamase
keywords: (+)-γ-Lactamase; (−)-γ-Lactamase; Biocatalysis; Enzymatic resolution; γ-Lactam