title: Quantitative analysis of residual folding and DNA binding in mutant p53 core domain: definition of mutant states for rescue in cancer therapy.
abstract: The tumour suppressor p53 is mutated in half of all human cancers, most frequently with missense substitutions in its core domain. We present a new assessment of the mutation database based on quantitative folding and DNA-binding studies of the isolated core domain. Our data identify five distinct mutant classes that correlate with four well-defined regions of the core domain structure. On extrapolation to 37 degrees C the wild-type protein has a stability of 3.0 kcal/mol. This also emerges as an oncogenic threshold: all beta-sandwich mutants destabilized by this amount (50% denatured) are expected to promote cancer. Other weakly destabilizing mutations are restricted to loop 3 in the DNA-binding region. Drugs that stabilize mutant p53 folding have the potential to reactivate apoptotic signalling pathways in tumour cells either by transactivation-dependent or independent pathways. Using an affinity ligand as a proof of principle we have recovered the thermodynamic stability of the hotspot G245S. With reference states for the five mutant classes as a guide, future therapeutic strategies may similarly stabilize partially structured or binding states of mutant p53 that restore limited p53 pathways to tumour suppression.
authors.affiliation: Cambridge University Chemical Laboratory and Cambridge Centre for Protein Engineering, Medical Research Council Centre, Hills Road, Cambridge CB2 2QH, UK.
authors.forename: A N
authors.initials: AN
authors.lastname: Bullock
authors.forename: J
authors.initials: J
authors.lastname: Henckel
authors.forename: A R
authors.initials: AR
authors.lastname: Fersht
mesh_terms: D017209:Apoptosis; D016208:Databases, Factual; D016158:Genes, p53; D006801:Humans; D008956:Models, Chemical; D008958:Models, Molecular; D009154:Mutation; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics; D011489:Protein Denaturation; D017510:Protein Folding; D011994:Recombinant Proteins / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013696:Temperature; D013816:Thermodynamics; D015533:Transcriptional Activation; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry*
chemical_list: D010446:Peptide Fragments; D011994:Recombinant Proteins; D016159:Tumor Suppressor Protein p53