1IOG:
reference: The relationship between insulin bioactivity and structure in the NH2-terminal A-chain helix., Olsen HB, Ludvigsen S, Kaarsholm NC, J Mol Biol 1998 Nov 27;284(2):477-88. PMID: 9813131

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