Dr. Pernecky's research uses the molecular genetic techniques of site-directed mutagenisis and deletion cloning to determine the contribution of structural features and conserved amino acids to the biochemical and biophysical properties of the xenobiotic-metabolizing P450 cytochromes. P450 enzymes are genetically fused to a glutathione S-transferase and expressed in bacteria; the fusion protein is isolated on a GSH(reduced glutathione)-agarose column and cleaved with protease between the fusion partners to obtain highly purified preparations.