Monoclonal antibody, a novel probe for protein folding

Two monoclonal antibodies (McAb2C9, McAb1E5) against Staphylococcal nuclease R (SNase R) and its N-terminal peptide fragments were prepared, purified and characterized. Further studies show that the intact enzyme SNase R and its seven N-terminal peptide fragments:differ in their interaction with McAb2C9. SNase R, SNR121, SNR102, SNR79 and SNR52 can bind to McAb2C9 readily, while fragments of SNR141, SNR135, SNR110 react with the antibody poorly. If this difference is due to diverse extent of exposure of the specific epitope in the fragments, it is suggested that the conformation of the peptide is subjected to continuous adjustments through chain elongation until the biologically active protein is formed. This result supports Tsou's hypothesis of nascent peptide folding experimentally.BiologySCI(E)1ARTICLE2163-1684