Kim Seung Il, Kweon Soo-Mi, Kim Eun A, Kim Jin Young, Kim Soohyun, Yoo Jong Shin, Park Young Mok
Proteome Analysis Team, Korea Basic Science Institute, Yoe-Eun Dong, Yusung-Ku, Daejeon, Republic of Korea.
J Plant Physiol. 2004 Jul;161(7):837-45. doi: 10.1016/j.jplph.2004.01.001.
The most abundant root proteins of ginseng (Panax ginseng) have been detected and identified by comparative proteome analysis with cultured hairy root of ginseng. Four abundant proteins (28, 26, 21 and 20 kDa) of P. ginseng had isoforms with different pl values on two-dimensional gel electrophoresis (2DE). The results of N-terminal and internal amino acid sequencing, however, showed that all of them originate from a 28 kDa protein, known as ginseng major protein (GMP). The GMP gene was searched for in the expressed sequence tag database of P. ginseng and found to encode a 27.3 kDa protein having 238 amino acid residues. Analysis of the amino acid sequences indicates that GMP exhibits high sequence homology with plant RNases and RNase-like proteins. However, purified GMP had no RNase activity even though it has conserved amino acid residues known to be essential for active sites of RNase. The GMPs present in ginseng main root were not expressed in cultured hairy roots of ginseng. 2DE analysis showed that the amounts of GMPs in main roots change according to seasonal fluctuation. These results suggest that the GMPs are root-specific RNase-like proteins, which function as vegetative storage proteins of ginseng for survival in the natural environment.
通过与人参培养毛状根的比较蛋白质组分析，已检测并鉴定出人参（Panax ginseng）中含量最丰富的根蛋白。人参的四种丰富蛋白质（28、26、21和20 kDa）在二维凝胶电泳（2DE）上具有不同pI值的同工型。然而，N端和内部氨基酸测序结果表明，它们均源自一种28 kDa的蛋白质，即人参主要蛋白（GMP）。在人参的表达序列标签数据库中搜索GMP基因，发现其编码一种具有238个氨基酸残基的27.3 kDa蛋白质。氨基酸序列分析表明，GMP与植物核糖核酸酶和核糖核酸酶样蛋白具有高度的序列同源性。然而，纯化的GMP没有核糖核酸酶活性，尽管它具有已知对核糖核酸酶活性位点至关重要的保守氨基酸残基。人参主根中存在的GMP在人参培养毛状根中不表达。2DE分析表明，主根中GMP的含量随季节波动而变化。这些结果表明，GMP是根特异性核糖核酸酶样蛋白，作为人参在自然环境中生存的营养贮藏蛋白发挥作用。
