3BG4:
reference: The crystal structure of guamerin in complex with chymotrypsin and the development of an elastase-specific inhibitor., Kim H, Chu TT, Kim DY, Kim DR, Nguyen CM, Choi J, Lee JR, Hahn MJ, Kim KK, J Mol Biol. 2008 Feb 8;376(1):184-92. Epub 2007 Dec 4. PMID: 18155725

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