%0 Journal Article
%A Onami, Yuika
%A Koya, Ryousuke
%A Kawasaki, Takayasu
%A Aizawa, Hiroki
%A Nakagame, Ryo
%A Miyagawa, Yoshito
%A Haraguchi, Tomoyuki
%A Akitsu, Takashiro
%A Tsukiyama, Koichi
%A Alcolea Palafox, Mauricio
%T Investigation by DFT Methods of the Damage of Human Serum Albumin Including Amino Acid Derivative Schiff Base Zn(II) Complexes by IR-FEL Irradiation
%D 2019
%@ 1422-0067
%U https://hdl.handle.net/20.500.14352/12606
%X An infrared free electron laser (IR-FEL) can decompose aggregated proteins by excitation of vibrational bands. In this study, we prepared hybrid materials of protein (human serum albumin; HSA) including several new Schiff base Zn(II) complexes incorporating amino acid (alanine and valine) or dipeptide (gly-gly) derivative moieties, which were synthesized and characterized with UV-vis, circular dichroism (CD), and IR spectra. Density functional theory (DFT) and time dependent DFT (TD-DFT) calculations were also performed to investigate vibrational modes of the Zn(II) complexes. An IR-FEL was used to irradiate HSA as well as hybrid materials of HSA-Zn(II) complexes at wavelengths corresponding to imine C=N, amide I, and amide II bands. Analysis of secondary structures suggested that including a Zn(II) complex into HSA led to the structural change of HSA, resulting in a more fragile structure than the original HSA. The result was one of the characteristic features of vibrational excitation of IR-FEL in contrast to electronic excitation by UV or visible light.
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