Abstract
Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOFMS) is a powerful and robust tool for protein identification. We proposed a novel MALDI method (UV/FEL MALDI) based on simultaneous irradiation of a nitrogen laser (UV) and a free electron laser (FEL) to perform selective ionization, improving sensitivity and extending the upper limit of detectable molecular weight. Simultaneous exposure of UV and FEL showed some advantages over conventional MALDI cases. First, tuning FEL to an absorption wavelength of the matrix advanced the ionization efficiency. Second, multimers of keratin were observed up to approximately 900 kDa. These results suggest that UV/FEL-MALDI can be a more effective method for functional analysis of macromolecules and supramolecules of proteins than conventional used of MALDI.
