Study on hemorrhagin III purified from the venom of Agkistrodon acutus by three-dimensional fluorescence spectrometry

摘要

The conformation changes of hemorrhagin III in different media were studied by three-dimensional fluorescence spectrometry (TDFS). It was found that the emission band of the protein remained centered at 344 nm for different excitation wavelengths in 0.1 percent sodium dodecyl sulfate (SDS) or in 0.05 percent cetyltrimethyl ammonium bromide (CTAB), as did that of apo-AaH III, while a red-shift occurred in 5.0 M guanidine hydrochloride (Gu-HCl). Changes in the environments of tryptophan (Trp) residues responsible for those in emission could be readily seen in the TDF contours. It was confirmed from the TDF spectra that Trp residues were mainly located in hydrophilic environments at the surface of the AaH III molecule. The experimental data showed that environments of Trp residues and protein conformational changes are effectively and directly revealed by TDFS.