ERG monoclonal antibody in the diagnosis and biological stratification of prostate cancer: delineation of minimal epitope, critical residues for binding, and molecular basis of specificity.

ERG monoclonal antibody in the diagnosis and biological stratification of prostate cancer: delineation of minimal epitope, critical residues for binding, and molecular basis of specificity. Monoclon Antib Immunodiagn Immunother. 2014 Aug;33(4):201-8 Authors: Rastogi A, Tan SH, Banerjee S, Sharad S, Kagan J, Srivastava S, McLeod DG, Srivastava S, Srinivasan A Abstract Recently we reported the development of a highly specific murine monoclonal antibody (ERG MAb 9FY) against the ERG oncoprotein. ERG is expressed in over half of all prostate cancers (CaP) as a result of specific gene fusions involving ERG and the androgen regulated TMPRSS2 promoter. ERG MAb 9FY has been extensively used in the evaluations of CaP. Increasing use of ERG MAb in CaP has prompted us to characterize the precise ERG epitope it binds to and to define the molecular basis of its specificity to ERG. The 9FY antibody binds to an epitope formed by amino acid residues 42-66 of the ERG protein. To determine the key residues involved in 9FY binding, experiments were carried out using a combination of approaches including overlapping peptides, alanine scanning mutagenesis, ELISA, and immunoblot assays. Analysis of both overlapping and variant peptides harboring truncations of amino acids revealed that a minimal epitope of eight residues (RVPQQDWL) is sufficient for binding to the 9FY antibody. In order to further identify key residues that mediate the binding of the anti...
Source: Monoclonal Antibodies in Immunodiagnosis and Immunotherapy - Category: Microbiology Tags: Monoclon Antib Immunodiagn Immunother Source Type: research