荧光法研究药物分子与人血清白蛋白的结合作用

Study on the Interaction of Human Serum Albumin and Drug Molecules by the Fluorescence Method

本文应用荧光光谱和能量转移技术首次研究了心血管病药物盐酸地尔硫(艹卓)、盐酸川芎嗪和甘草酸三种药物分子与人血清白蛋白的结合作用.研究结果表明,盐酸川芎嗪和盐酸地尔硫(艹卓)在溶液中与白蛋白形成缔合物,荧光猝灭机理符合静态机制,缔合物的稳定常数分别为:盐酸川芎嗪K_s=1.12×10~4(mol/L)^(-1)(25℃),K_s=6.95×10~3(mol/L)^(-1)(40℃);盐酸地尔硫(艹卓)K_s=4.71×10~2(mol/L)^(-1)(25℃),K_s=3.00×10~2(mol/L)^(-1)(40℃)、甘草酸与白蛋白的作用符合动态猝灭机理,动态猝灭常数为K_D=4.76×10~2(mol/L)^(-1)(25℃),K_D=6.19×10~2(mol/L)^(-1)(40℃).基于F(?)rster偶极-偶极无辐射能量转移机理确定了药物分子盐酸川芎嗪在人血清白蛋白中与第214位色氨酸残基之间的距离R=1.76nm(25℃),R=1.80nm(40℃).

In this paper, applying fluorescence quenching method and energy transfer technique, we have firstly studied the interaction of human serum albumin (HSA) with cardiovascular drugs such as dilthiazem, tetramethylpyrazine and glycyrrhizic acid. The results show that dilthiazem and tetramethylpyrazine can form association molecules with HSA in the solution. The mechanism of quenching belongs to static quenching and the association constants between tetramethylpyrazine and HSA are KS = 1.12×104 (mol/ L)-1(25℃), 6.95×103 (mol/ L)-1(40℃), and those between dilthiazem and HSA are 4.71 ×102(mol/ L)-1(25℃), 3.00×102(mol/ L)-1 (40℃), respectively. The interaction between HSA and glycyrrhizic acid is dynamic quenching. The dynamic quenching constants are KD = 4.16×102(mol/ L)-1(25℃), 6.19×102(mol/ L)-1 (40℃). Based on the mechanism of energy transfer of dipole-dipole interaction between the donor and acceptor, we have determined the distance between 214-tryptophane residue of HSA and drug molecule tetramethylpyrazine to be R = 1.76nm(25℃) and 1.80nm(40℃), respectively.