Fourier transform IR and Fourier transform Raman spectroscopy studies of metallothionein-III: amide I band assignments and secondary structural comparison with metallothioneins-I and -II.
The secondary structures of porcine brain Cu(4)Zn(3)-metallothionein (MT)-III and Cd(5)Zn(2)MT-I, Cd(5)Zn(2)MT-II, and Zn(7)MT-I from rabbit livers in the solid state are investigated by Fourier transform IR spectroscopy (FTIR) and Fourier transform Raman spectroscopy (FT-Raman). The Cu(4)Zn(3)MT-III contains 26-28% beta-turns and half-turns, 13-14% 3(10)-helices, 47-49% random coils, and 11-12% beta-extended chains. The structural comparison of porcine brain Cu(4)Zn(3)MT-III with rabbit liver Cd(5)Zn(2)MT-I (II) and Zn(7)MT-I shows that the contents of the random coil structure are obviously increased. The results indicate that the insert of an acidic hexapeptide in the alpha domain of Cu(4)Zn(3)MT-III possibly forms an alpha helix. However, because the bands assigned to the alpha-helix and random coil structures are overlapped in the spectra, the content of random coil structures in Cu(4)Zn(3)MT-III is therefore higher than those in Cd(5)Zn(2)MT-I, Cd(5)Zn(2)MT-II, and Zn(7)MT-I.
Shi
Yan-Bo
YB
State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, Nanjing University, Nanjing 210093, China.
Fang
Jiang-Lin
JL
Liu
Xiao-Yu
XY
Du
Liang
L
Tang
Wen-Xia
WX
D000577:Amides / Q000032:analysis*; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001923:Brain Chemistry; D003198:Computer Simulation; D008099:Liver / Q000737:chemistry; D008668:Metallothionein / Q000737:chemistry* / Q000302:isolation & purification; D000090023:Metallothionein 3; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000302:isolation & purification; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011817:Rabbits; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013552:Swine
D000577:Amides; D000596:Amino Acids; D000090023:Metallothionein 3; D009419:Nerve Tissue Proteins; D008668:Metallothionein