Mutation of surface residues to promote crystallization of activated factor XI as a complex with benzamidine: an essential step for the iterative structure-based design of factor XI inhibitors.Jin, L., Pandey, P., Babine, R.E., Weaver, D.T., Abdel-Meguid, S.S., Strickler, J.E.
(2005) Acta Crystallogr.,Sect.D 61: 1418-1425
- PubMed: 16204896
- DOI: 10.1107/S0907444905024340
- Primary Citation of Related Structures:  1ZHM, 1ZHP
- Also Cited By: 2FDA
- PubMed Abstract:
Activated factor XI (FXIa) is a key enzyme in the amplification phase of the blood-coagulation cascade. Thus, a selective FXIa inhibitor may have lesser bleeding liabilities and provide a safe alternative for antithrombosis therapy to available drugs ...
Activated factor XI (FXIa) is a key enzyme in the amplification phase of the blood-coagulation cascade. Thus, a selective FXIa inhibitor may have lesser bleeding liabilities and provide a safe alternative for antithrombosis therapy to available drugs on the market. In a previous report, the crystal structures of the catalytic domain of FXIa (rhFXI(370-607)) in complex with various ecotin mutants have been described. However, ecotin forms a matrix-like interaction with rhFXI(370-607) and is impossible to displace with small-molecule inhibitors; ecotin crystals are therefore not suitable for iterative structure-based ligand design. In addition, rhFXI(370-607) did not crystallize in the presence of small-molecule ligands. In order to obtain the crystal structure of rhFXI(370-607) with a weak small-molecule ligand, namely benzamidine, several rounds of surface-residue mutation were implemented to promote crystal formation of rhFXI(370-607). A quadruple mutant of rhFXI(370-607) (rhFXI(370-607)-S434A,T475A,C482S,K437A) readily crystallized in the presence of benzamidine. The benzamidine in the preformed crystals was easily exchanged with other FXIa small-molecule inhibitors. These crystals have facilitated the structure-based design of small-molecule FXIa inhibitors.
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