芦丁对血清白蛋白构象的影响

用同步荧光光谱法和圆二色谱法研究了芦丁对牛血清白蛋白(BSA)和人血清白蛋白(HSA)构象和功能的影响，同时用电化学方法研究了芦丁与血清白蛋白之间的结合作用。在体内随着芦丁浓度的增加，其与血清白蛋白结合时对血清白蛋白的构象无影响，但对血清白蛋白的二级结构有影响，导致α-螺旋结构减少，β-折叠结构增加，蛋白质的二级结构被破坏。电化学研究发现：芦丁的氧化还原电流随着血清白蛋白浓度的增加而明显降低， 表明芦丁与血清白蛋白发生反应，生成比较稳定的复合物。芦丁的氧化还原最大峰电位也随着血清白蛋白浓度的增加发生变化，峰电位差略增加，表明芦丁的氧化还原性随着血清白蛋白浓度的增加而增强。进一步证明芦丁在体内能够被血清白蛋白存储和转运。

Influence of Rutin on Conformation of Serum Albumin

We studied the effect of the rutin on the conformation of bovine serum albumin (BSA) and human serum albumin (HSA) by synchronous fluorescence spectrum(Δλ＝λ_em-λ_ex=15 nm and Δλ＝λ_em-λex=60 nm) and circular dichroism spectra. The results showed that rutin had hardly effect on the serum protein conformation, but influenced the secondary structure of serum albumin (SA) molecule with the addition of rutin into BSA and HSA solution. The α-helix structure of BSA and HSA was decreased and the β-sheet was increased with the increase in rutin concentration. At the same time, we studied the binding of rutin and bovine serum albumin (BSA) and human serum albumin (HSA) by electrochemistry under physiological condition. Cyclic voltammograms of rutin demonstrated a pair of well-reversible peaks in the solution of Tris-NaCl buffer at pH 7.38(sweep rate: 50 mV·s-1; a glassy carbon working electrode, a platinum auxiliary electrode, and a saturated calomel reference electrode). Both peak potentials of rutin were Epc=0.103 2 V and E_pa=0.150 6 V, ipc∶ipa=1∶1.2, the dispersion of peak potential was 47.4 mV (ΔE_prutin=ΔE_pc-E_pa=47.4 mV). In addition, with the addition of BSA and HSA into the rutin solution, both the reduction and oxidation currents decreased only at the peak potentials of rutin (BSA：E_pc=0.114 1 V, E_pa=0.168 5 V, ipc∶ipa=1∶1.2；HSA：E_pc=0.114 2 V, E_pa=0.168 8 V, ipc∶ipa=1∶1.1)，the dispersions of peak potential were changed: for BSA ΔE_prutin=E_pc-E_pa=54.4 mV, and for HSA: ΔE_prutin=E_pc-E_pa=54.6 mV. The results showed that there was an interaction of rutin with BSA and HSA, forming a kind of nonelectroactive supramolecular complex, and indicated that rutin could be deposited and transported by serum protein in vivo.