Influence of Rutin on Conformation of Serum Albumin
WU Jin-xiu1,ZHANG Yin1,LI Mei1,SONG Yu-min2
1. College of Rare Earth, Inner Mongolia University of Science and Technology, Baotou 014010, China 2. College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
Abstract：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＝λem-λex=15 nm and Δλ＝λem-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 Epa=0.150 6 V, ipc∶ipa=1∶1.2, the dispersion of peak potential was 47.4 mV (ΔEprutin=ΔEpc-Epa=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：Epc=0.114 1 V, Epa=0.168 5 V, ipc∶ipa=1∶1.2；HSA：Epc=0.114 2 V, Epa=0.168 8 V, ipc∶ipa=1∶1.1)，the dispersions of peak potential were changed: for BSA ΔEprutin=Epc-Epa=54.4 mV, and for HSA: ΔEprutin=Epc-Epa=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.
