Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1235446 | Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2007 | 4 Pages |
Abstract
This paper discussed the quantitative influence of Cu(II) on the interaction between horseradish peroxidase (HRP) and sulfite (SO32â), which is a derivate of sulfite dioxide in human bodies, by using fluorescence spectrum and ultraviolet (UV) absorption spectrometry in vitro. The results show that under the conditions of physiological pH and room-temperature, Cu(II) can bind strongly with both the protein part and the ferroporphyrin part in HRP at a low concentration (10â4 mol Lâ1), and the combination constants are 2.047 Ã 103 and 7.66 Ã 102 L molâ1, respectively. Under the same conditions, SO32â at low concentrations (<0.15 mol Lâ1) has little quenching for the fluorescence of HRP at 330 nm, and the combination constant is 0.108 L molâ1. While the fluorescence intensity at 440 nm enhance gradually with the increased concentration of SO32â (<0.1 mol Lâ1), and the combination constant is 8.219 L molâ1. These indicate that SO32â at low concentration has little reaction with the enzyme protein part in HRP but obvious reaction with the ferroporphyrin part in HRP. After SO32â at low concentrations is added into the HRP-Cu(II) binary system, the reaction constants between SO32â and the enzyme protein part in HRP increase rapidly. Compared with the absence of Cu(II), the combination constant of SO32â with the enzyme protein part in HRP increases nearly 70 times with a certain Cu(II) concentration (5.0 Ã 10â4 mol Lâ1) in the system. However, the presence of Cu(II) in the system has little effect on the reaction constants between SO32â and the ferroporphyrin part in HRP.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Jie Lan, Dong-Sheng Guo, Xiao-Ying Yuan,