Nakane H, Ono K
Laboratory of Viral Oncology, Aichi Cancer Center Research Institute, Nagoya, Japan.
Biochemistry. 1990 Mar 20;29(11):2841-5. doi: 10.1021/bi00463a029.
The two components of Camellia sinensis (tea plant) [i.e., (-)-epicatechin gallate and (-)-epigallocatechin gallate] were found to differentially inhibit the activities of reverse transcriptase and cellular DNA and RNA polymerases. Under the assay conditions optimized for each enzyme species, the strongest inhibition by these compounds was observed with reverse transcriptase. The concentrations of (-)-epicatechin gallate and (-)-epigallocatechin gallate required for 50% inhibition of the activity of human immunodeficiency virus (HIV) reverse transcriptase were in the range of 0.01-0.02 microgram/mL. On the other hand, neither (-)-epicatechin, (-)-epigallocatechin, nor gallic acid, the constituents of (-)-epicatechin gallate and (-)-epigallocatechin gallate, was inhibitory to the activity of HIV reverse transcriptase at concentrations up to 1 microgram/mL. The mode of inhibition of reverse transcriptase and other DNA polymerases by these compounds was competitive with respect to the template-primer, whereas the mode of inhibition of RNA polymerase was competitive with respect to the nucleotide substrate. The Ki values of HIV reverse transcriptase for (-)-epicatechin gallate and (-)-epigallocatechin gallate were determined to be 7.2 and 2.8 nM, respectively, which are smaller by 1-2 orders of magnitude than the Ki's of other DNA and RNA polymerases for these compounds.
人们发现茶树（Camellia sinensis）的两种成分[即（-）-表儿茶素没食子酸酯和（-）-表没食子儿茶素没食子酸酯]对逆转录酶以及细胞DNA和RNA聚合酶的活性具有不同的抑制作用。在针对每种酶优化的测定条件下，这些化合物对逆转录酶的抑制作用最强。抑制人类免疫缺陷病毒（HIV）逆转录酶活性50%所需的（-）-表儿茶素没食子酸酯和（-）-表没食子儿茶素没食子酸酯的浓度范围为0.01 - 0.02微克/毫升。另一方面，（-）-表儿茶素、（-）-表没食子儿茶素以及（-）-表儿茶素没食子酸酯和（-）-表没食子儿茶素没食子酸酯的成分没食子酸，在浓度高达1微克/毫升时对HIV逆转录酶的活性均无抑制作用。这些化合物对逆转录酶和其他DNA聚合酶的抑制模式相对于模板引物而言是竞争性的，而对RNA聚合酶的抑制模式相对于核苷酸底物而言是竞争性的。HIV逆转录酶对（-）-表儿茶素没食子酸酯和（-）-表没食子儿茶素没食子酸酯的Ki值分别测定为7.2和2.8纳摩尔，比其他DNA和RNA聚合酶对这些化合物的Ki值小1 - 2个数量级。
