ISSN:
0170-2041
Keywords:
Phalloidin, MD calculations in water, 2D NMR, conformational analysis
;
Amanita phalloides
;
Calculations, MD; GROMOS
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Homo- and heteronuclear NMR techniques have been used to assign all proton and most of the carbon resonances of phalloidin (1) [cyclic(L-alanyl-D-threonyl-L-cysteinyl-cis-4-hydroxy-L-prolyl-L-alanyl-L-mercapto-L-tryptophyl-4,5-dihydroxy-L-leucyl) cyclic (3→6) sulfide], a toxic bicyclic heptapeptide of the poisonous mushroom Amanita phalloides. Intramolecular proton-proton distances derived from rotating-frame NOE experiments have been used as constraints in energy minimization and molecular dynamics calculations using GROMOS. Charge reduction of solvent-exposed NH protons has been used to minimize artifacts in the in vacuo calculation. The structure has been proven to be unstable without constraints in vacuo. Hence, a procedure is proposed in which first restrained MD in vacuo is performed and refinement is carried out by restrained or unrestrained MD in water.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.199119910132
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