Affiliations: Department of Food and Nutritional Sciences,
University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan | Laboratory of Biotechnology, Department of Citrus
Research, Okitsu NIFTS NARO, 485-6 Shimizu-Okitsu Nakamachi, Shizuoka 424-0292,
Japan
Note: [] Address for correspondence: Tsutomu Nakayama, Department of Food
and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526,
Japan. Tel.: +81 54 264 5522; Fax: +81 54 264 5551; E-mail:
nakayatu@smail.u-shizuoka-ken.ac.jp
Abstract: γ-Terpinene is a monoterpene and a major component of
essential oils made from citrus fruits and shows strong antioxidant activity in
various assay systems. Plant γ-terpinene synthase is a member of the
monoterpene cyclase family, which produces a specific monoterpene through
cyclization of geranyl diphosphate (GPP), but the monoterpene cyclases have not
been fully characterized. It is necessary to prepare large amounts of
γ-terpinene synthase from Citrus unshiu (Satsuma mandarin) for the
characterization, on this purpose we expressed the protein in Escherichia
coli (E. coli) cells. As most monoterpene synthases have plastid-targeting
signals, a gene lacking these signals was prepared and functionally expressed
in E. coli cells harboring extra copies of the argU gene. The purified
enzyme was incubated with GPP and the main product was confirmed to
beγ-terpinene by GC/MS.
