3RDY

Crystal Structure of buckwheat trypsin inhibitor rBTI at 1.84 angstrom resolution

Summary for 3RDY

• Entry DOI: 10.2210/pdb3rdy/pdb
• Related: 3RDZ
• Descriptor: BWI-1=PROTEASE inhibitor/trypsin inhibitor (2 entities in total)
• Functional Keywords: serine protease inhibitor, potato inhibitor i, trypsin inhibitor, trypsin, hydrolase inhibitor
• Biological source: Fagopyrum esculentum (buckwheat)
• Total number of polymer chains: 1
• Total formula weight: 9019.24

Authors

Wang, L.F.,Li, M.,Chang, W.R. (deposition date: 2011-04-02, release date: 2011-07-06, Last modification date: 2024-10-30)

Primary citation

Wang, L.F.,Zhao, F.,Li, M.,Zhang, H.,Gao, Y.,Cao, P.,Pan, X.,Wang, Z.,Chang, W.R.
Conformational Changes of rBTI from Buckwheat upon Binding to Trypsin: Implications for the Role of the P(8)' Residue in the Potato Inhibitor I Family
Plos One, 6:e20950-e20950, 2011

PubMed Abstract: BWI-1 (buckwheat trypsin inhibitor), a member of the potato inhibitor I family, suppresses the growth of T-acute lymphoblastic leukemia cells and induces apoptosis in human solid tumor cell lines. Here, we report the crystal structure of rBTI (recombinant buckwheat trypsin inhibitor), a recombinant protein of BWI-1, at 1.84 Å resolution and the structure of rBTI in complex with bovine trypsin at 2.26 Å resolution. A conformational change of Trp53 at the P(8)' position in rBTI was observed upon its binding to trypsin, which is not seen in other members of the potato inhibitor I family reported previously. The role of the P(8)' residue in the potato inhibitor I family was examined by measuring the association and dissociation rates of four rBTI mutants with different substitutions at the P(2) and P(8)' positions when binding to trypsin. One of the mutants, P44T, was found to be a much stronger inhibitor than wild-type rBTI, with a picomolar (pM) dissociation constant. Our results could provide valuable insights for designing a new rBTI-based antitumor drug in the future.

PubMed: 21698291
DOI: 10.1371/journal.pone.0020950

Experimental method

X-RAY DIFFRACTION (1.84 Å)