1VIB:
reference: Structure of neurotoxin B-IV from the marine worm Cerebratulus lacteus: a helical hairpin cross-linked by disulphide bonding., Barnham KJ, Dyke TR, Kem WR, Norton RS, J Mol Biol 1997 May 23;268(5):886-902. PMID: 9180379

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