HOLLOW-FIBER FLOW FIELD-FLOW FRACTIONATION:A GENTLE SEPARATION METHOD FOR MASS SPECTROMETRY OF NATIVE PROTEINS

摘要

Low-impact ionization sources like electrospray ionization(ESI)and matrix-assisted,laser desorption/ionization(MALDI)equipped with time-of-flight(TOF)mass analyzers provide intact protein analysis over a very wide molar mass range. ESI/TOFMS provides also indications on the higher-order structure of intact proteins and non-covalent protein complexes.However,direct analysis of intact proteins mixtures in real samples shows limited success,mainly because spectra become very complex to interpret. This is also due to sample contaminants,and to the mechanism of competitive ionization in ESI or MALDI. Rapid and efficient sample clean-up and separation methods can significantly enhance the power of TOFMS for intact protein analysis. However,if protein native conditions want to be maintained,the methods should affect neither the three-dimensional structure nor the non-covalent chemistry of the proteins.