Patent ID: 9046525
Filing Date: 2015-06-02
Classification: G01N

Abstract:
1. A method of determining the number of protein subunits in a protein complex, the method, comprising: tagging a protein subunit of the protein complex to form a tagged protein subunit comprising a peptide tag and a protease cleavage site between the peptide tag and the protein subunit; expressing the tagged protein subunit in a cell culture or a cell-free extract to form a tagged protein complex comprising expressed tagged protein subunits; selectively digesting the tagged protein complex at at least two different time points with a protease to form an analyte mixture comprising undigested protein complex, intermediate reaction products, and/or digested protein complex; separating the undigested protein complex, the intermediate reaction products, and/or the digested complex of the analyte mixture; and determining the number of protein subunits in the protein complex by analyzing the presence of, or the progressive loss of, the peptide tag in each of the undigested protein complex, the intermediate reaction products, and/or the digested protein complex.