The binding reaction between methyl pheophorbide-a-Gd (MPA-Gd) and Human Serum Albumins (HSA) was studied by fluorescence and UV-Vis absorption spectra. The results indicated that the binding reaction of them was a si...The binding reaction between methyl pheophorbide-a-Gd (MPA-Gd) and Human Serum Albumins (HSA) was studied by fluorescence and UV-Vis absorption spectra. The results indicated that the binding reaction of them was a single static quenching process, MPA-Gd strongly bound HSA, the binding equilibrium constant K0=2.298×105 L·mol-1 at 25 ℃. The shortest binding distance(r) and energy transfer efficiency(E) between donor (HSA) and acceptor (MPA-Gd) was obtained by Frster′s nonradiative energy transfer mechanism as follows: r=4.03 nm, E=0.12. The enthalpy change (ΔH) and entropy change (ΔS) were calculated at 25 and 37 ℃. The results indicated that the hydrogen bonds played major role in the reaction. Furthermore, the displacement experiments indicated that MPA-Gd could bind to the site Ⅱof HSA.展开更多
Holographic recording analysis was performed on the films that were sensitized with ammonium dichromate with albumin of hen and quail (Gallus gallus and Callipepla cali) as abiopolymeric photosensitive matrix. The sam...Holographic recording analysis was performed on the films that were sensitized with ammonium dichromate with albumin of hen and quail (Gallus gallus and Callipepla cali) as abiopolymeric photosensitive matrix. The samples were exposed to an He-Cd laser, λ = 442 nm, at various concentrations, and diffraction efficiencies were measured as a function to the energy, thickness, protein density, aging time, and spatial frequencies. The photosensitivity was measured as a function of storage time, and the gratings were recorded in real time. The photochemical processes involved in the formation of holographic image are described. The results indicate the behavior of colloidal systems based on albumin bird build holographic recording materials.展开更多
The binding characteristics of indigotin with human serum albumin （HSA） and bovine serum albumin （BSA） have been investigated by various spectroscopic techniques. Spectroscopic analysis revealed that the quenching...The binding characteristics of indigotin with human serum albumin （HSA） and bovine serum albumin （BSA） have been investigated by various spectroscopic techniques. Spectroscopic analysis revealed that the quenching mechanism between indigotin and HSA/BSA belonged to the static quenching. The displacement experiments suggested that indigotin primarily bound to tryptophan residues on proteins within site I. The thermodynamic parameters indicated that the binding of indigoti^HSA/BSA mainly depended on the hydrophobic interaction. The binding distance of indigotin to HSA/BSA was evaluated. The results by synchronous fluorescence, three- dimensional fluorescence, Fourier Transform Infrared spectroscopy （FT-IR） and circular dichroism （CD） spectra showed that the conformation of proteins altered in the presence of indigotin.展开更多
The mechanisms and effects about the interaction between serum albumins and silver nanoparticles have been intensively studied by means of transmission electron microscopy (TEM), circular dichroism (CD) and ultraviole...The mechanisms and effects about the interaction between serum albumins and silver nanoparticles have been intensively studied by means of transmission electron microscopy (TEM), circular dichroism (CD) and ultraviolet-visible (UV-Vis) spectroscopy. The adsorption of serum al-bumins on the surface of silver nanoparticles is observed by TEM. The studies with the surface plasmon bands indicate that the electrostatic and hydrophilic interactions are the major forces be-tween serum albumins and silver nanoparticles; the number of adsorbed monolayer serum albu-min molecules to a silver nanoparticle with the size of 60 nm is about 6.7×105. The far-UV CD spectra provide the evidence that the secondary structure of adsorbed serum albumins adopt a looser and more extended conformation, in which the content of -helix decreases, whereas the content of -sheet, turn and unordered coil increases. Using time-scanning UV-Vis spectra to monitor the interacting process, the particular twofold hysteresis effects are significantly found with the coverage of aggregated silver nanoparticles and the conformational transition of serum albumins, respectively. The rate constants and the thermodynamics parameters about the hysteretic processes are also calculated.展开更多
The binding reaction between 10-hydroxycamptothecin （10-HCPT） and human serum albumins （HSA） is studied by means of fluorescence spectroscopy, UV-Vis absorption spectrum, IH NMR spectrum, and molecular simulation....The binding reaction between 10-hydroxycamptothecin （10-HCPT） and human serum albumins （HSA） is studied by means of fluorescence spectroscopy, UV-Vis absorption spectrum, IH NMR spectrum, and molecular simulation. The results indicate that the binding reaction of 10-HCPT and HSA is a single static quenching process, and the binding equilibrium constant for 10-HCPT binding with HSA is estimated K0-4.93×10^4 L · mol-I at 25 ℃ with the molar ratio of I ： 1. The distance （r） and energy transfer efficiency（E） between donor （HSA） and acceptor （10-HCPT） are obtained as follows, r=3.51 nm; E-0.27. The enthalpy change （△Hφ） and entropy change （△Sφ） are calcu- lated at different temperatures, and the hydrophobic force and shidipole force are the functions in the reaction. The results show that 10-HCPT binds within the subdomain II A of HSA by the hydrophobic force, and the 10-OH and 20-OH of 10-HCPT bind with both residue Leu-238 of HSA and Ala 291 of HSA by hydrogen bonds.展开更多
文摘The binding reaction between methyl pheophorbide-a-Gd (MPA-Gd) and Human Serum Albumins (HSA) was studied by fluorescence and UV-Vis absorption spectra. The results indicated that the binding reaction of them was a single static quenching process, MPA-Gd strongly bound HSA, the binding equilibrium constant K0=2.298×105 L·mol-1 at 25 ℃. The shortest binding distance(r) and energy transfer efficiency(E) between donor (HSA) and acceptor (MPA-Gd) was obtained by Frster′s nonradiative energy transfer mechanism as follows: r=4.03 nm, E=0.12. The enthalpy change (ΔH) and entropy change (ΔS) were calculated at 25 and 37 ℃. The results indicated that the hydrogen bonds played major role in the reaction. Furthermore, the displacement experiments indicated that MPA-Gd could bind to the site Ⅱof HSA.
基金Thanks are due to The Instituto Nacional de Astrofisica Optica y Electronica(INAOE)for the infrastructure and economic support received.
文摘Holographic recording analysis was performed on the films that were sensitized with ammonium dichromate with albumin of hen and quail (Gallus gallus and Callipepla cali) as abiopolymeric photosensitive matrix. The samples were exposed to an He-Cd laser, λ = 442 nm, at various concentrations, and diffraction efficiencies were measured as a function to the energy, thickness, protein density, aging time, and spatial frequencies. The photosensitivity was measured as a function of storage time, and the gratings were recorded in real time. The photochemical processes involved in the formation of holographic image are described. The results indicate the behavior of colloidal systems based on albumin bird build holographic recording materials.
基金support by the Education Department of Sichuan Province (12ZA171)
文摘The binding characteristics of indigotin with human serum albumin （HSA） and bovine serum albumin （BSA） have been investigated by various spectroscopic techniques. Spectroscopic analysis revealed that the quenching mechanism between indigotin and HSA/BSA belonged to the static quenching. The displacement experiments suggested that indigotin primarily bound to tryptophan residues on proteins within site I. The thermodynamic parameters indicated that the binding of indigoti^HSA/BSA mainly depended on the hydrophobic interaction. The binding distance of indigotin to HSA/BSA was evaluated. The results by synchronous fluorescence, three- dimensional fluorescence, Fourier Transform Infrared spectroscopy （FT-IR） and circular dichroism （CD） spectra showed that the conformation of proteins altered in the presence of indigotin.
基金This work was supported by the National Natural Science Foundation of China(Grant No.20261001)CEMFoundation for N&T Joint Academythe Science Foundation of Guangxi Zhuang Autonomous Region.
文摘The mechanisms and effects about the interaction between serum albumins and silver nanoparticles have been intensively studied by means of transmission electron microscopy (TEM), circular dichroism (CD) and ultraviolet-visible (UV-Vis) spectroscopy. The adsorption of serum al-bumins on the surface of silver nanoparticles is observed by TEM. The studies with the surface plasmon bands indicate that the electrostatic and hydrophilic interactions are the major forces be-tween serum albumins and silver nanoparticles; the number of adsorbed monolayer serum albu-min molecules to a silver nanoparticle with the size of 60 nm is about 6.7×105. The far-UV CD spectra provide the evidence that the secondary structure of adsorbed serum albumins adopt a looser and more extended conformation, in which the content of -helix decreases, whereas the content of -sheet, turn and unordered coil increases. Using time-scanning UV-Vis spectra to monitor the interacting process, the particular twofold hysteresis effects are significantly found with the coverage of aggregated silver nanoparticles and the conformational transition of serum albumins, respectively. The rate constants and the thermodynamics parameters about the hysteretic processes are also calculated.
基金Supported by the Foundation of Shandong Province Educa-tion Bureau (J06060)
文摘The binding reaction between 10-hydroxycamptothecin （10-HCPT） and human serum albumins （HSA） is studied by means of fluorescence spectroscopy, UV-Vis absorption spectrum, IH NMR spectrum, and molecular simulation. The results indicate that the binding reaction of 10-HCPT and HSA is a single static quenching process, and the binding equilibrium constant for 10-HCPT binding with HSA is estimated K0-4.93×10^4 L · mol-I at 25 ℃ with the molar ratio of I ： 1. The distance （r） and energy transfer efficiency（E） between donor （HSA） and acceptor （10-HCPT） are obtained as follows, r=3.51 nm; E-0.27. The enthalpy change （△Hφ） and entropy change （△Sφ） are calcu- lated at different temperatures, and the hydrophobic force and shidipole force are the functions in the reaction. The results show that 10-HCPT binds within the subdomain II A of HSA by the hydrophobic force, and the 10-OH and 20-OH of 10-HCPT bind with both residue Leu-238 of HSA and Ala 291 of HSA by hydrogen bonds.
