The interactions of HSA with DA have received great attention nowadays due to its significant effect in the biomedical field and overall health. The main aim of this work is to examine the interaction between DA and H...The interactions of HSA with DA have received great attention nowadays due to its significant effect in the biomedical field and overall health. The main aim of this work is to examine the interaction between DA and HSA at physiological conditions. Upon addition of DA to HSA, the fluorescence emission was quenched with quenching constant Kq = 1.32 × 109 L⋅mol−1⋅s−1 and the binding constant of DA with HSA is found to be K = 4.4 × 102 mainly indicating dynamic quenching. The HSA conformation was altered upon binding of DA to HSA with an increase in α-helix and a decrease in β-sheets suggesting unfolding of HSA secondary structure due to weak intermolecular interaction with HSA. In view of the evidence presented, it is important to understand the details of the interactions of HSA with DA which will be crucial in the design of new DA-inspired drugs and help revealing vital details to better understand the HSA’s role as a transporter for many drugs.展开更多
Beta amyloid (Aβ) aggregation has been characterized to be responsible for several amyloid diseases. Fourier transform infrared (FTIR) spectroscopy, fluorescence, and atomic force microscopy (AFM) are used to investi...Beta amyloid (Aβ) aggregation has been characterized to be responsible for several amyloid diseases. Fourier transform infrared (FTIR) spectroscopy, fluorescence, and atomic force microscopy (AFM) are used to investigate induced changes in the secondary structure of Aβ upon thermal denaturation and interaction with propofol and L-arginine. Spectral analysis has revealed an effective static quenching for the intrinsic fluorescence of Aβ by propofol and l-arginine with binding constants of 2.81 × 102 M-1 for Aβ-propofol and 0.37 × 102 M-1 for Aβ-L-arginine. Fourier self-deconvolution (FSD) technique has been used to evaluate the relative intensity changes in the spectra of the component bands in the amide I and amide II regions at different ligand’s concentration in the protein complex. The analysis showed a decrease in the intensities of the parallel beta bands of propofol and L-arginine interactions with Aβ, accompanied with an increase in the antiparallel bands for the Aβ-propofol interaction and a decrease for the Aβ-l-arginine interaction. The relative increase in peaks’ intensities at 1694 cm-1 and 1531 cm-1 for the propofol interaction is linked to the formation of oligomers in the protein.展开更多
文摘The interactions of HSA with DA have received great attention nowadays due to its significant effect in the biomedical field and overall health. The main aim of this work is to examine the interaction between DA and HSA at physiological conditions. Upon addition of DA to HSA, the fluorescence emission was quenched with quenching constant Kq = 1.32 × 109 L⋅mol−1⋅s−1 and the binding constant of DA with HSA is found to be K = 4.4 × 102 mainly indicating dynamic quenching. The HSA conformation was altered upon binding of DA to HSA with an increase in α-helix and a decrease in β-sheets suggesting unfolding of HSA secondary structure due to weak intermolecular interaction with HSA. In view of the evidence presented, it is important to understand the details of the interactions of HSA with DA which will be crucial in the design of new DA-inspired drugs and help revealing vital details to better understand the HSA’s role as a transporter for many drugs.
文摘Beta amyloid (Aβ) aggregation has been characterized to be responsible for several amyloid diseases. Fourier transform infrared (FTIR) spectroscopy, fluorescence, and atomic force microscopy (AFM) are used to investigate induced changes in the secondary structure of Aβ upon thermal denaturation and interaction with propofol and L-arginine. Spectral analysis has revealed an effective static quenching for the intrinsic fluorescence of Aβ by propofol and l-arginine with binding constants of 2.81 × 102 M-1 for Aβ-propofol and 0.37 × 102 M-1 for Aβ-L-arginine. Fourier self-deconvolution (FSD) technique has been used to evaluate the relative intensity changes in the spectra of the component bands in the amide I and amide II regions at different ligand’s concentration in the protein complex. The analysis showed a decrease in the intensities of the parallel beta bands of propofol and L-arginine interactions with Aβ, accompanied with an increase in the antiparallel bands for the Aβ-propofol interaction and a decrease for the Aβ-l-arginine interaction. The relative increase in peaks’ intensities at 1694 cm-1 and 1531 cm-1 for the propofol interaction is linked to the formation of oligomers in the protein.
