Author:
Bai Peixian,Wang Liyuan,Wei Kang,Ruan Li,Wu Liyun,He Mengdi,Ni Dejiang,Cheng Hao
Abstract
Abstract
Background
Alanine decarboxylase (AlaDC), specifically present in tea plants, is crucial for theanine biosynthesis. Serine decarboxylase (SDC), found in many plants, is a protein most closely related to AlaDC. To investigate whether the new gene AlaDC originate from gene SDC and to determine the biochemical properties of the two proteins from Camellia sinensis, the sequences of CsAlaDC and CsSDC were analyzed and the two proteins were over-expressed, purified, and characterized.
Results
The results showed that exon-intron structures of AlaDC and SDC were quite similar and the protein sequences, encoded by the two genes, shared a high similarity of 85.1%, revealing that new gene AlaDC originated from SDC by gene duplication. CsAlaDC and CsSDC catalyzed the decarboxylation of alanine and serine, respectively. CsAlaDC and CsSDC exhibited the optimal activities at 45 °C (pH 8.0) and 40 °C (pH 7.0), respectively. CsAlaDC was stable under 30 °C (pH 7.0) and CsSDC was stable under 40 °C (pH 6.0–8.0). The activities of the two enzymes were greatly enhanced by the presence of pyridoxal-5′-phosphate. The specific activity of CsSDC (30,488 IU/mg) was 8.8-fold higher than that of CsAlaDC (3467 IU/mg).
Conclusions
Comparing to CsAlaDC, its ancestral enzyme CsSDC exhibited a higher specific activity and a better thermal and pH stability, indicating that CsSDC acquired the optimized function after a longer evolutionary period. The biochemical properties of CsAlaDC might offer reference for theanine industrial production.
Publisher
Springer Science and Business Media LLC
Reference37 articles.
1. Saeed M, Naveed M, Arif M, Kakar MU, Manzoor R, El-Hack MEA, Alagawany M, Tiwari R, Khandia R, Munjal A, et al. Green tea (Camellia sinensis) and L-theanine: medicinal values and beneficial applications in humans-a comprehensive review. Biomed Pharmacother. 2017;95:1260–75.
2. Yang Z, Baldermann S, Watanabe N. Recent studies of the volatile compounds in tea. Food Res Int. 2013;53(2):585–99.
3. Kim TI, Lee YK, Park SG, Choi IS, Ban JO, Park HK, Nam S-Y, Yun YW, Han SB, Oh KW, et al. L-Theanine, an amino acid in green tea, attenuates beta-amyloid-induced cognitive dysfunction and neurotoxicity: reduction in oxidative damage and inactivation of ERK/p38 kinase and NF-kappa B pathways. Free Radic Biol Med. 2009;47(11):1601–10.
4. Wei K, Ruan L, Li H, Wu L, Wang L, Cheng H. Estimation of the effects of major chemical components on the taste quality of green tea. Int Food Res J. 2019;26(3):869–76.
5. Kaneko S, Kumazawa K, Masuda H, Henze A, Hofmann T. Molecular and sensory studies on the umami taste of Japanese green tea. J Agric Food Chem. 2006;54(7):2688–94.
Cited by
6 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献