2STB:
reference: High-resolution structures of three new trypsin-squash-inhibitor complexes: a detailed comparison with other trypsins and their complexes., Helland R, Berglund GI, Otlewski J, Apostoluk W, Andersen OA, Willassen NP, Smalas AO, Acta Crystallogr D Biol Crystallogr 1999 Jan;55 ( Pt 1):139-48. PMID: 10089404

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