2NBT:
reference: Solution structure of neuronal bungarotoxin determined by two-dimensional NMR spectroscopy: calculation of tertiary structure using systematic homologous model building, dynamical simulated annealing, and restrained molecular dynamics., Sutcliffe MJ, Dobson CM, Oswald RE, Biochemistry 1992 Mar 24;31(11):2962-70. PMID: 1550821

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).