Spectroscopic characterization of textilotoxin, a presynaptic neurotoxin from the venom of the Australian eastern brown snake (Pseudonaja t. textilis).
Spectroscopic behavior of textilotoxin, from the venom of Pseudonaja t. textilis, and its subunits were investigated using fluorescence, circular dichroism and Fourier transform infrared spectroscopy. Circular dichroism spectra of the B, C and D subunits indicate considerable similarity in their alpha-helix and beta-sheet contents. By contrast, the A subunit displays significantly more beta-sheet and 'remainder' structure. FTIR spectra confirm conclusions drawn from CD spectra. Fluorescence spectra indicate that, in general, tryptophan residues in the A, B and D subunits are relatively exposed to the solvent. The C subunit exhibits no fluorescence, suggesting a lack of tryptophan. Comparisons of individual subunit spectra with those of the intact toxin suggest that significant changes in secondary structure may occur when the toxin dissociates.
Department of Molecular Biology, University of Wyoming, Laramie 82071.
S D
SD
Aird
C R
CR
Middaugh
I I
II
Kaiser
D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D004546:Elapid Venoms / Q000302:isolation & purification*; D046911:Macromolecular Substances; D009498:Neurotoxins / Q000302:isolation & purification*; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence
D004546:Elapid Venoms; D046911:Macromolecular Substances; D009498:Neurotoxins; C037525:textilotoxin