QUANTITATIVE ANALYSIS OF PROTEIN ISOFORMS USING MATRIX-ASSISTED LASER DESORPTION/IONIZATION TIME OF FLIGHT MASS SPECTROMETRY

摘要

The present invention provides for methods of quantitating the amounts of proteins or peptides, including those that are closely related isoforms, usi ng matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS). Measurement of protein concentrations in vivo has been extremely difficult and problematic, and protein concentrations have not bee n shown to correlate well with mRNA levels, the standard used in the past. The present invention overcomes the deficiencies of prior methodologies by takin g advantage of MALDI-TOF-MS technology and applying it to proteins and peptide s in a way that allows for accurate, quantitative measurement in vivo of prote in or peptide concentrations.