Scientists identify L-lysine decarboxylases from Huperzia serrata in the biosynthesis of huperzine A
On January 12 2017, the research paper entitled “Identification and characterization of L-lysine decarboxylase from Huperzia serrata and its role in the metabolic pathway of lycopodium alkaloid” has been published online in Phytochemistry. In this report, a key gene, ldc which is responsible for decarboxylation of L-lyine named as L-lysine decarboxylase (LDC) was identified from Huperzia serrata. The metabolic role in the biosynthesis of Huperzine A (HupA) was characterized as well by coupling with copper amine oxidase (CAO).
HupA, one of the pyridine skeleton lycodine, was firstly isolated from the Chinese folk medicinal herb Qian Ceng Ta (Huperzia serrata). Since HupA was found to possess potent acetylcholinesterase inhibition (AChEI) effect and had been clinically used for the treatment of Alzheimer’s disease (AD) for years in China. On the basis of feeding experiments before, the first two biosynthetic steps for lycopodium alkaloids are believed involving the decarboxylation of lysine to cadaverine followed by the oxidative deamination of cadaverine to 5-aminopentanal. In this study, six previously undescribed HsLDCs were isolated with degenerate PCR and RACEs (rapid amplification of cDNA ends). The evidence provided from in vitro and in vivo experiments in tobacco (Nicotiana benthamiana) suggested that this enzyme identified in this study (HsLDC-X1) functions in decarboxylation of lysine. The copper amine oxidase (CAO) from Huperzia serrata has been identified before. Additionally, with a novel method developed, the enzymatic products of HsLDC and HsCAO, namely cadaverine and 5-aminopentanal, respectively, were detected simultaneously both in assay with purified enzymes and in transgenic tobacco leaves. This research makes up the HupA biosynthesis pathway study and paves the way for engineering production of this alkaloid.
This research was performed by Baofu Xu
et al from
Prof. XIAO Youli’s group at CAS Center for Excellence in Molecular Plant Sciences, CAS Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, CAS. The work was financially supported by the Science and Technology Commission of Shanghai Municipality, and CAS-JIC Centre of Excellence in Plant and Microbial Sciences (CEPAMS) funding.
