摘要：植物品种培育的关键是寻找优良基因.通过理性设计对植物关键酶进行改造,有望为植物品种培有提供新的优良基因.NtGGPPSI是烟草类胡萝卜素合成途径的限速酶,ntggppsl突变体类胡萝卜含量显著降低.对NtGGPPS1进行理性设计,重塑酶与底物的结合口袋,构建单点饱和突变体文库.通过高通量的细菌颜色实验进行筛选,获.得5个可以显著提升酶活性的氨基酸位点,进一步对以上位点进行迭代组合突变获得酶活性最高的5突变体d-NtGGPPS1(V154A/1161L/F218Y/1209S/V233E).相对于NtGGPPSI,理性设计的d-NtGGPPSI可以将底物IPP和共同底物DMAPP转化为GGPP的效率提高约1995.5倍,能够将GPP或FPP转化产生GGPP的效率提高约25.9或16.7倍.将d-NtGGPPSI回补到ntggppsI突变体可以显著提升叶片类胡萝卜含量,生物量及光合作用效率.该研究表明理性设计GGPPS可以提升植物的产量和品质性状,并为未来通过理性设计获得植物优良基因提供新的突破口.

摘要：The mitogen-activated protein kinase (MAPK) cell signal transduction pathways play a key role in determining the survival of cells. If these pathways can be controlled, they will prohibit the proliferation of cancer cells. To attain this goal, the authors utilize many drugs to interact with mitogen-activated protein kinase kinase-1 (MEK1) in MAPK, and use computer aided drug design (CADD) to analyze the ligand activities of proteins in MEK1. The results show that in these drugs, the aromatic group in the terminal of the protein and the PHE209 will induce the stacking force, which is highly related to the actual activities of these drugs.