Conformational Differences of an Immunosuppressant Peptolide in a Single Crystal and in a Crystal Complex with Human Cyclophilin A.
Mikol, V., Taylor, P., Kallen, J., Walkinshaw, M.D.(1998) J Mol Biol 283: 451
- PubMed: 9769217 
- DOI: https://doi.org/10.1006/jmbi.1998.2109
- Primary Citation of Related Structures:  
1CWO - PubMed Abstract: 
The crystal structure of (Thr2, Leu5, d-Hiv8, Leu10)-cyclosporin (cyclic peptolide SDZ 214-103) has been determined as the unbound crystal form and as a complex with human cyclophilin A. This pair of structures provides an example of a significant difference in conformation between free and bound ligand in crystals. The conformation of the unbound form is unlike that of both free and bound conformations of cyclosporin A (with the amide bond between residues 3 and 4 in the cis conformation), while the bound conformation is similar to that of CsA bound to cyclophilin. The cyclophilin-bound conformations of both ligands are similar, though this involves a significantly different waterellipsisligand hydrogen-bonding structure, which compensates for the chemical differences between the two ligands.
Organizational Affiliation: 
The University of Edinburgh, Michael Swann Building, Edinburgh, EH9 3JR, UK.