Abstract: The present invention relates to a method for screening for agents which modulate the binding of p53 to p300, and agents identified using such an assay. Such agents include peptide mimetics of regions of p53 and/or p300 which have been identified as contact region for the other protein. The agents of the present invention are candidates for use in the treatment of, for example cancer, or ischemia.

Abstract: A class of mutant forms of p53 protein, such as His273 and Lys285, which are defective in conversion from the latent to the activated state by casein kinase II, but with the ability to be activated for specific DNA binding by the action of ligands such as monoclonal antibody PAb421 and heat shock protein DnaK. Activation of these mutants, which are found at high levels in certain types of tumour, can potentially lead to selective growth arrest and induction of apoptosis in the tumor cells. p53 can be constitutively activated also by deletion of the C-terminal 30 amino acids. p53 activated in this way, or by ligand binding, can be administered for the purposes of tumour or cell growth suppression.