Time Resolved Fluorescence Energy Transfer (TR-FRET) Assay: The inhibition of p53-MDM2 and p53-MDM4 interactions is measured by time resolved fluorescence energy transfer (TR-FRET). Fluorescence energy transfer (or Foerster resonance energy transfer) describes an energy transfer between donor and acceptor fluorescent molecules. For this assay, human MDM2 protein (amino acids 2-188) and human MDM4 protein (amino acids 2-185), tagged with a C-terminal biotin moiety, are used in combination with a Europium labeled streptavidin (Perkin Elmer, Inc., Waltham, MA, USA) serving as the donor fluorophore. The p53 derived, Cy5 labeled peptide Cy5-TFSDLWKLL (p53 aa18-26) is the energy acceptor. Upon excitation of the donor molecule at 340nm, binding interaction between MDM2 or MDM4 and the p53 peptide induces energy transfer and enhanced response at the acceptor emission wavelength at 665 nm.
Time Resolved Fluorescence Energy Transfer (TR-FRET) Assay: The inhibition of p53-MDM2 and p53-MDM4 interactions is measured by time resolved fluorescence energy transfer (TR-FRET). Fluorescence energy transfer (or Foerster resonance energy transfer) describes an energy transfer between donor and acceptor fluorescent molecules. For this assay, human MDM2 protein (amino acids 2-188) and human MDM4 protein (amino acids 2-185), tagged with a C-terminal biotin moiety, are used in combination with a Europium labeled streptavidin (Perkin Elmer, Inc., Waltham, MA, USA) serving as the donor fluorophore. The p53 derived, Cy5 labeled peptide Cy5-TFSDLWKLL (p53 aa18-26) is the energy acceptor. Upon excitation of the donor molecule at 340nm, binding interaction between MDM2 or MDM4 and the p53 peptide induces energy transfer and enhanced response at the acceptor emission wavelength at 665 nm.
Inhibition of C-terminal biotin-tagged streptavidin labelled human MDM2 ( 2 to 188 residues)/Cy5-labelled p53 (18 to 26 residues)(unknown origin) interaction after 15 mins by TR-FRET assay
Antiproliferative activity against MDM2 amplified human SJSA1 cells assessed as reduction in cell growth after 72 hrs by YO-PRO1-iodine staining based fluorescent assay
Antiproliferative activity against human Saos2 cells expressing wild type p53 assessed as reduction in cell growth after 72 hrs by YO-PRO1-iodine staining based fluorescent assay