Bak S, Olsen C E, Petersen B L, Møller B L, Halkier B A
Plant Biochemistry Laboratory, Department of Plant Biology, Royal Veterinary and Agricultural University, 40 Thorvaldsensvej, DK-1871 Frederiksberg C, Copenhagen, Denmark.
Plant J. 1999 Dec;20(6):663-71. doi: 10.1046/j.1365-313x.1999.00642.x.
Glucosinolates are natural products in cruciferous plants, including Arabidopsis thaliana. CYP79A1 is the cytochrome P450 catalysing the conversion of tyrosine to p-hydroxyphenylacetaldoxime in the biosynthesis of the cyanogenic glucoside dhurrin in sorghum. Both glucosinolates and cyanogenic glucosides have oximes as intermediates. Expression of CYP79A1 in A. thaliana results in the production of high levels of the tyrosine-derived glucosinolate p-hydroxybenzylglucosinolate, which is not a natural constituent of A. thaliana. This provides further evidence that the enzymes have low substrate specificity with respect to the side chain. The ability of the cyanogenic CYP79A1 to integrate itself into the glucosinolate pathway has important implications for an evolutionary relationship between cyanogenic glucosides and glucosinolates, and for the possibility of genetic engineering of novel glucosinolates.
硫代葡萄糖苷是十字花科植物中的天然产物，包括拟南芥。CYP79A1是一种细胞色素P450，在高粱中氰基葡萄糖苷苦杏仁苷的生物合成过程中催化酪氨酸转化为对羟基苯乙醛肟。硫代葡萄糖苷和氰基葡萄糖苷都以肟作为中间体。CYP79A1在拟南芥中的表达导致产生高水平的酪氨酸衍生硫代葡萄糖苷对羟基苄基硫代葡萄糖苷，这不是拟南芥的天然成分。这进一步证明了这些酶对侧链的底物特异性较低。氰基CYP79A1整合到硫代葡萄糖苷途径中的能力对于氰基葡萄糖苷和硫代葡萄糖苷之间的进化关系以及新型硫代葡萄糖苷基因工程的可能性具有重要意义。
