3CI7:
reference: Crystal structure of an extensively simplified variant of bovine pancreatic trypsin inhibitor in which over one-third of the residues are alanines., Islam MM, Sohya S, Noguchi K, Yohda M, Kuroda Y, Proc Natl Acad Sci U S A. 2008 Oct 7;105(40):15334-9. Epub 2008 Sep 30. PMID: 18829434

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