Kobayashi N, Endo S, Kobayashi H, Faulstich H, Wieland T, Munekata E
Institute of Applied Biochemistry, University of Tsukuba, Japan.
Eur J Biochem. 1995 Sep 15;232(3):726-36.
We investigated the conformations of toxic phalloidin and viroisin in aqueous solution using 500-MHz 1H-NMR spectroscopy in conjunction with molecular modeling. The conformations of two non-toxic phalloidin derivatives, secophalloidin and dethiophalloidin, were also correspondingly studied for comparison purposes. Results indicate that the non-toxic peptides have a multiple conformation, whereas the toxic peptides are comprised of a rigid molecule. It was found that the conformation of phalloidin partially resembles that of viroisin in the region of Cys3-Pro4-Ala5-Trp6, being different from that of the non-toxic peptides; thereby suggesting this region plays an important role leading to their toxicity.
