Primary Citation of Related Structures:   1TMT, 1TMU
PubMed Abstract: 
The three-dimensional structures of D-Phe-Pro-Arg-chloromethyl ketone-inhibited thrombin in complex with Tyr-63-sulfated hirudin (ternary complex) and of thrombin in complex with the bifunctional inhibitor D-Phe-Pro-Arg-Pro-(Gly)4-hirudin (CGP 50,856, binary complex) have been determined by X-ray crystallography in crystal forms different from those described by Skrzypczak-Jankun et al ...
The three-dimensional structures of D-Phe-Pro-Arg-chloromethyl ketone-inhibited thrombin in complex with Tyr-63-sulfated hirudin (ternary complex) and of thrombin in complex with the bifunctional inhibitor D-Phe-Pro-Arg-Pro-(Gly)4-hirudin (CGP 50,856, binary complex) have been determined by X-ray crystallography in crystal forms different from those described by Skrzypczak-Jankun et al. (Skrzypczak-Jankun, E., Carperos, V.E., Ravichandran, K.G., & Tulinsky, A., 1991, J. Mol. Biol. 221, 1379-1393). In both complexes, the interactions of the C-terminal hirudin segments of the inhibitors binding to the fibrinogen-binding exosite of thrombin are clearly established, including residues 60-64, which are disordered in the earlier crystal form. The interactions of the sulfate group of Tyr-63 in the ternary complex structure explain why natural sulfated hirudin binds with a 10-fold lower K(i) than the desulfated recombinant material. In this new crystal form, the autolysis loop of thrombin (residues 146-150), which is disordered in the earlier crystal form, is ordered due to crystal contacts. Interactions between the C-terminal fragment of hirudin and thrombin are not influenced by crystal contacts in this new crystal form, in contrast to the earlier form. In the bifunctional inhibitor-thrombin complex, the peptide bond between Arg-Pro (P1-P1') seems to be cleaved.
Related Citations: 
Structure of the Hirugen and Hirulog Complexes of Alpha-Thrombin Skrzypczak-Jankun, E., Carperos, V.E., Ravichandran, K.G., Tulinsky, A. (1991) J Mol Biol 221: 1379
Refined Structure of the Hirudin-Thrombin Complex Rydel, T.J., Tulinsky, A., Bode, W., Huber, R. (1991) J Mol Biol 221: 583
Crystal Structure of the Thrombin-Hirudin Complex: A Novel Mode of Serine Protease Inhibition Gruetter, M.G., Priestle, J.P., Rahuel, J., Grossenbacher, H., Bode, W., Hofsteenge, J., Stone, S.R. (1990) EMBO J 9: 2361
The Refined 1.9 Angstrom Crystal Structure of Human Alpha Thrombin: Interaction with D-Phe-Pro-Arg Chloromethylketone and Significance of the Tyr-Pro-Pro-Trp Insertion Segment Bode, W., Mayr, I., Baumann, U., Huber, R., Stone, S.R., Hofsteenge, J. (1989) EMBO J 8: 3467
Organizational Affiliation: 
Department of Biotechnology, Ciba-Geigy Ltd., Basel, Switzerland.