Überführung der Faktor Xa Bindetasche in Trypsin: Ein Modellsystem für das Verständnis von Protein ? Ligand ? Wechselwirkungen und zur Charakterisierung von Selektivitätsdeterminanten

In order to design selective high affinity ligands to a target protein, it is necessary to understand the structural determinants for protein ? ligand complex formation. Previous experiments to introduce the factor Xa ligand binding site into trypsin resulted in variants that exhibited conformational variability with reduced affinity for factor Xa selective inhibitors. In the present study, the effects of specific mutations designed to stabilise / destabilise individual conformations are characterised both structurally and kinetically using a variety of inhibitors. In general, conformational variability results in a reduction in ligand affinity. This reduction can be partially or wholly offset by compensatory binding to a particular conformation. The insights provided by these studies will be helpful in improving our understanding of ligand binding for the drug design process.