NMR structural determination of viscotoxin A3 from Viscum album L.
This structure was determined using standard 2D homonuclear techniques
1010 distance restraints were calculated reduced to 734 (230 intraresidue, 172 sequential, 191 medium range, 141 long range) after removal of irrelevant restraints. Calculation started with 200 randomized conformers and consistently violated restraints were checked and relaxed where necessary. This procedure was repeated until no consistent violations were found in half or more of the structures. 600 new calculations were started and the 20 structures with lowest target function were analyzed. The structure with lowest target function and the structure exhibiting the largest RMSD with it were subjected to restrained molecular dynamics (20 cycles of 15 ps restrained molecular dynamics followed by minimization). All even structures from the last 10 minimized structures were retained from both sets and deposited.
RESTRAINED SIMULATED ANNEALING IN TORSION ANGLE SPACE, ITERATIVE RESTRAINTS REFINEMENT, RESTRAINED MOLECULAR DYNAMICS IN CARTESIAN COORDINATE SPACE MINIMIZATION
lowest average rmsd with other structures in the ensemble
2mM Viscotoxin A3 1H; 50mM H3PO4/NaOH aqueous buffer; 90% H2O, 10% D2O
2mM Viscotoxin A3 1H; 50mM H3PO4/NaOH aqueous buffer; 100% D2O
Eccles, Xia, Bartels, Guentert, Billeter, Wuethrich
THIONIN, CONCENTRIC MOTIF, HELIX-TURN-HELIX, ALPHA-BETA PROTEIN, AMPHIPATHIC HELIX, TOXIN