Basyuni Mohammad, Oku Hirosuke, Inafuku Masashi, Baba Shigeyuki, Iwasaki Hironori, Oshiro Keichiro, Okabe Takafumi, Shibuya Masaaki, Ebizuka Yutaka
United Graduate School of Agricultural Sciences, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan.
Phytochemistry. 2006 Dec;67(23):2517-24. doi: 10.1016/j.phytochem.2006.09.016. Epub 2006 Oct 31.
Homology based PCRs with degenerate primers designed from the conserved sequences among the known oxidosqualene cylases (OSCs) have resulted in cloning of a triterpene synthase (KcMS) from the young roots of Kandelia candel (L.) Druce (Rhizophoraceae). KcMS consists of a 2286 bp open reading frame, which codes for 761 amino acids. The deduced amino acid sequence showed 79% homology to a lupeol synthase from Ricinus communis suggesting it to be a lupeol synthase of K. candel. KcMS was expressed in a lanosterol synthase deficient yeast with the expression vector pYES2 under the control of GAL1 promoter. GC-MS analysis showed that the transformant accumulated a mixture of lupeol, beta-amyrin and alpha-amyrin in a 2:1:1 ratio, indicating that KcMS encodes a multifunctional triterpene synthase, although it showed high sequence homology to a R. communis lupeol synthase. This is the first OSC cloning from mangrove tree species.
利用根据已知氧化鲨烯环化酶（OSC）的保守序列设计的简并引物进行基于同源性的聚合酶链式反应（PCR），已从秋茄（Kandelia candel (L.) Druce，红树科）的幼根中克隆出一种三萜合酶（KcMS）。KcMS由一个2286 bp的开放阅读框组成，编码761个氨基酸。推导的氨基酸序列与蓖麻（Ricinus communis）的羽扇豆醇合酶有79%的同源性，表明它是秋茄的羽扇豆醇合酶。KcMS在带有表达载体pYES2的羊毛甾醇合酶缺陷型酵母中，在GAL1启动子的控制下表达。气相色谱-质谱联用（GC-MS）分析表明，转化体积累了羽扇豆醇、β-香树脂醇和α-香树脂醇的混合物，比例为2:1:1，这表明KcMS编码一种多功能三萜合酶，尽管它与蓖麻羽扇豆醇合酶具有高度的序列同源性。这是首次从红树树种中克隆出OSC。
