1F2S:
reference: Crystal structure of the complex formed between bovine beta-trypsin and MCTI-A, a trypsin inhibitor of squash family, at 1.8-A resolution., Zhu Y, Huang Q, Qian M, Jia Y, Tang Y, J Protein Chem. 1999 Jul;18(5):505-9. PMID: 10524768

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