- 作者: 陳億霖,邱顯泰
- 作者服務機構: Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 300, Taiwan, R.O.C.
- 中文摘要: trans,trans-Farnesyl diphosphate (FPP) serves as a universal substrate for a large family of sesquiterpene cyclases that are responsible for biosynthesis of more than 300 structurally diverse sesquiterpenes in nature. A new FPP substrate analogue, 12-fluoro-farnesylphosphonophosphate (12-F-F-CH2PP), was synthesized in this paper for applications on kinetic and mechanistic studies of the enzyme family. Trichodiene synthase (TS), a sesquiterpene cyclase, catalyzes the conversion of trans,trans-farnesyl diphosphate (FPP) to trichodiene. 12-F-F-CH2PP was tested as a potential inhibitor of TS. Inactivation and inhibition kinetic experiments showed that 12-F-F-CH2PP was not a mechanism-based inactivator for TS; instead, a mixed-type reversible inhibition was observed with inhibition constants Ki1 = 2.33 ± 0.50 mM and Ki2 = 25.80 ± 7.70 mM, values close to those previously determined for farnesylphosphonophosphate, Ki1 = 3.25 mM and Ki2 = 9.10 mM. Although 12-F-F-CH2PP did not irreversibly inactivate TS, this new analogue serves as a potential active-site directed inactivator and mechanistic probe of other sesquiterpene cyclases and FPP-utilizing enzymes, which utilize FPP as a common acyclic substrate.
- 英文摘要: --
- 中文關鍵字: Sesquiterpene cyclases; Enzyme kinetics; Terpenes; Biosynthesis; Enzyme inhibitors.
- 英文關鍵字: --