期刊
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
卷 436, 期 -, 页码 -出版社
ELSEVIER SCIENCE SA
DOI: 10.1016/j.jphotochem.2022.114425
关键词
Bovine hemoglobin; Coumarin derivatives; Fluorescence; Quenching; Molecular docking
This study investigated the molecular recognition of bovine hemoglobin with 7-hydroxycou-marin and 4-methyl-7-hydroxycoumarin. The results showed that the binding of these fluorescent compounds to hemoglobin is reversible and occurs through a static quenching mechanism. Hydrophobic forces and hydrogen bonding play important roles in the binding process.
Biological functioning takes place through the interaction of biomacromolecules with each other or with other small molecules. The molecular recognition of a carrier protein, bovine hemoglobin (BHb), with 7-hydroxycou-marin (7-HC) and 4-methyl-7-hydroxycoumarin (4-Me-7-HC) was investigated using various biophysical and computational techniques. Fluorescence spectroscopy and molecular docking revealed the interaction of 7-HC and 4-Me-7-HC with beta 2-Trp37 fluorophore, quenching the intrinsic fluorescence of BHb. The mechanism of quenching was determined to be static. The binding constant (Kb) for BHb with 7-HC and 4-Me-7-HC was found to be 6.15 x 104 M-1 and 5.73 x 104 M-1 at 298 K, respectively. This moderate form of protein-ligand asso-ciation could result in reversible binding to transport and release the ligand in the target tissue. Negative Delta G for both complexes suggested spontaneous binding. Positive Delta H and Delta S for BHb-7-HC indicated hydrophobic forces played a dominant role in binding. However, hydrogen bonding and hydrophobic forces dictated the binding process for BHb-4-Me-7-HC due to obtaining negative Delta H and positive Delta S values. Changes in the microenvi-ronment of the binding site were observed through 3D fluorescence studies. Through Fo center dot rster resonance energy transfer (FRET), a binding distance of less than 7 nm was measured between BHb and 7-HC/4-Me-7-HC. The interaction of coumarin derivatives with BHb resulted in a loss of alpha-helical content of the protein, as proven by circular dichroism (CD) and Fourier transform infrared (FTIR) measurements. Molecular dynamic simulations showed the binding of 7-HC supplemented the stability of BHb, whereas 4-Me-7-HC binding resulted in conformational changes in the structure of BHb.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据