title: Over-expression of the human MDM2 p53 binding domain by fusion to a p53 transactivation peptide.
abstract: MDM2 binds to the tumor suppressor protein p53 and regulates the level of p53 in cells. Although it is possible to prepare a small amount of the region of MDM2 that binds to p53, the expression level of this fragment of MDM2 is relatively low, limiting the studies involving this protein. Here, we describe a construct for the optimized bacterial expression and purification of the MDM2 p53 binding domain. We found that the expression level of the soluble MDM2 p53 binding domain in bacteria was increased dramatically by fusing it to its interaction partner, the p53 transactivation peptide. Attachment of the p53 transactivation peptide (residues 17-29) to the N-terminus of MDM2 resulted in a more than 200-fold increase of soluble protein expression of the p53 binding domain in bacteria. To obtain the final MDM2 p53 binding domain (residues 5-109) we inserted a tobacco etch virus protease recognition site between the P53 peptide and the MDM2 p53 binding domain. To weaken the protein/peptide interaction and facilitate the separation of the protein from the complex, we introduced a point mutation of one of the key interaction residues (F19A or W23A) in the p53 peptide. The advantages of our new construct are high yield and easy purification of the MDM2 protein.
authors.affiliation: Global Pharmaceutical Discovery Division, Abbott Laboratories, Abbott Park, IL 60064, USA. zhihong.liu@abbott.com
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Liu
authors.forename: Edward T
authors.initials: ET
authors.lastname: Olejniczak
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Fesik
mesh_terms: D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009687:Nuclear Proteins / Q000737:chemistry / Q000502:physiology*; D010455:Peptides / Q000737:chemistry; D017354:Point Mutation; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011518:Proto-Oncogene Proteins / Q000737:chemistry / Q000502:physiology*; D051736:Proto-Oncogene Proteins c-mdm2; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015533:Transcriptional Activation; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000378:metabolism*
chemical_list: D009687:Nuclear Proteins; D010455:Peptides; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; D016159:Tumor Suppressor Protein p53; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2