Specifically, we have recently analysed the binding of steroids to antiprogesterone antibody DB3. In the work we calculated the affinities of steroids to the antibody and by doing computational mutagenesis rationalised the binding differences at the level of individual amino acid residues. We have carried out MD simulations and applied various trajectory analysis methods to probe the effects of amino acid mutations on protein motion. MD simulations have also been used to help explain the role of helix 12 of the ligand-binding domain of vitamin D3 receptor for the partial agonism of carboxylic ester antagonists (in collaboration with Prof. C. Carlberg, Univ. of Kuopio). We are developing computational tools for protein structure modelling and novel approaches for quantitative structure-activity relationship analysis.