互隔交链孢霉提取物261—B2—3在体外对DNA、RNA和蛋白质合成的影响

大多数化学致癌物均可影响DNA、RNA和蛋白质合成的过程。本文研究了从食管癌高发区林县粮食中分离出的互隔交链孢霉菌株261提取物261-B_2-3对这些大分子物质合成的影响。研究表明261-B_2-3对DNA和蛋白质的合成有明显的抑制,其作用强度呈明显的浓度相关性。但是它对RNA的合成无明显影响。三种大分子物质的合成对于261-B_2-3的敏感性顺序为:蛋白质>DNA>RNA。261-B_2-3对DNA和蛋白质抑制作用的类型和机理并不相同。在中止261-B_2-3的作用后,DNA的合成率持续下降,形成一谷值,属于模板损伤型,而蛋白质则呈递增型合成曲线,为干扰代谢型。261-B_2-3对大分子合成的干扰导致了细胞生物学和生化过程的紊乱,并有可能在诱变过程中起到一定作用。

Effect of extract of alternaria alternata on the synthesis of DNA, RNA and proteins

It was known that most chemical carcinogens could interfere with the synthesis of DNA, RNA and protein. The effect of 261-B_2-3, an extract of Alternaria alternata separated from Linxian county which is a high risk area of esophageal cancer in North China interference on the metabolism of these macromolectules was studied. Experi- ments showed that the synthesis of DNA and protein were partially blocked after exposing to 261-B_2-3 and the inhibition rate showed a relationship to the concentration of 261-B_2-3, but 261-B_2-3 gave no evidence of interference of RNA metabolism. Experiments demostrated the difference of action of 261-B_2-3 as inhibiting agent in DNA and protein synthesis. The rate of DNA synthesis decreased with time after the removal of 261-B_2-3 from medium and a valley was found in the curveof DNA synthesis. In contrast to the results with DNA synthesis, the rate of protein increased immediately after the removal of the agent. 261-B_2-3 is regarded as a DNA-damaging agent that inhibits protein synthe sis but does not damage it. The interference of the macromolecules by 261-B_2-3 leads to confusion of cell biology and biochemistry and may play an important role in mutagenicity.