Search PubMed⌕ Search

Biomedical subjects

T Wieland

Publications and source records attributed to T Wieland.

At least 145 records · Page 8Linked to original sources
PubMed1974

Interaction of phalloidin with actin.

Phalloidin, a toxic bicyclic peptide of rapid action from the toadstool, Amanita phalloides, gives rise to polymerization of G-actin to filamentous structures (Ph-actin) in a medium of low ionic strength. Ph-actin closely resembles the microfilaments found in liver membrane fractions (Ph-filaments) after in vivo or in vitro poisoning. Both phalloidin induced filaments are resistant to 0.6 M KI in contrast to F-actin, and become decorated by heavy meromyosin. After preincubation with cytochalasin B significantly fewer actin filaments are observed.

Actins↗
PubMed1973

Conformations of the li-antamanide complex and na-[phe, val]antamanide complex in the crystalline state.

Antamanide, a cyclic decapeptide isolated from the poisonous mushroom Amanita phalloides, preferably complexes with Na(+), but in less polar solvents, e.g., acetonitrile, also with Li(+) or K(+). The selectivity of complexation makes it an important model for the study of conformational requirements of ion binding. The conformations of the lithium antamanide complex and the Na-[Phe(4), Val(6)]antamanide complex have been established by x-ray diffraction analyses of single crystals. The two compounds are isostructural, but not isomorphous. The complexes are folded into a globular shape with an approximate 2-fold axis. Two of the peptide linkages are in the cis conformation, Pro(2)-Pro(3) and Pro(7)-Pro(8). There are only two intramolecular hydrogen bonds. Four C==O groups have their O atoms directed inward to form four Li-O or Na-O ligands. The fifth ligand to the metal ion is provided by a solvent molecule. The conformation found in the crystalline state is different from any of the conformations proposed for the sodium antamanide complex in solution on the basis of nuclear magnetic resonance data.

Journal Article↗