[Study on thermal unfolding process of trichosanthin by FTIR spectroscopy].
Fourier-transform infared spectroscopy, combined with resolution-enhancement techniques including second-derivative spectroscopy, Fourier self-deconvolution and curvefitting technique, was used to investigate the thermally induced unfolding process of anti-HIV-I toxin protein trichosanthin. During heating from 25 degrees C to 85 degrees C, the peak of Amide I shifted to 1618 cm-1 while the secondary structural contents change with the temperature. Upon cooling the protein from 85 degrees C to 25 degrees C, the contour of the Amide I do not change. All these show that the thermal unfolding of trichosanthin is an irreversible intermolecular aggregation process between 25 degrees C and 85 degrees C. The changes of secondary structures with temperature suggest the presence of folding intermediates.
Bian
W
W
Department of Chemistry, Tsinghua University, 100084 Beijing.
Sun
S
S
Wong
R N
RN
Zhou
Q
Q
Hu
X
X
D006358:Hot Temperature; D011487:Protein Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D017550:Spectroscopy, Fourier Transform Infrared; D015978:Trichosanthin / Q000737:chemistry*
D015978:Trichosanthin