BSA体系中2,4-D和阿特拉津对性激素的干扰机理

在2,4-D和阿特拉津以及天然性激素(雌二醇、睾酮)中加入牛血清白蛋白(BSA),通过紫外吸收峰的变化、温度与体系荧光强度的关系、以及计算扩散碰撞猝灭常数Kq等方法确定2,4-D和阿特拉津均可以发生类似天然性激素和BSA间的基态络合.并通过双倒数公式计算出各自二元体系的结合常数.2,4-D、阿特拉津、雌二醇、睾酮与BSA的结合常数(K)均在104数量级,可以认为2,4-D和阿特拉津具有与天然性激素相近的对BSA结合能力,并可通过竞争占据结合位点的方式干扰正常性激素与BSA的结合.

THE DISRUPTING MECHANISM OF 2,4-D, ATRAZINE FOR SEX HORMONES IN BAS SYSTEM

Environmental endocrine distrapting chemicals(EDCs') disrupting effect on the balance of sex hormones,the interaction between 2,4-D,Atrazine and bovine serum albumin(BSA) was studied with ultraviolet spectroscopy and fluorescence analysis,which was also compared with that of natural sex hormones (estradiol,testosterone) in BSA system.The results show that both sex hormones and 2,4-D have strong ability to affect the fluorescence intensity of BSA,and the interaction between 2,4-D,Atrazine and BSA is just similar with that of estradiol,testosterone.It is suggested complexe formed between2,4-D,Atrazine(sex hormones) and BSA,which is conformed by the concentration-dependent variation of ultraviolet absorption peak,the temperature-dependent behavior of fluorescence intensity,and the quenching constant K_(q)calculated with Stern-Volmer formula.Moreover,the binding constant K of estradiol,testosterone,2,4-D and Atrazine in BSA system were calculated with Lineweaver-Burk method.similar values of K were showed in all these systems,which(suggested) that the binding capability of 2,4-D,Atrazine and sex hormones is similar,therefore,the normal binding between sex hormones with serum albumin can be disrupted by the competitively binding of 2,4-D and Atrazine.