Trypsin-based monolithic bioreactor coupled on-line with LC/MS/MS system for protein digestion and variant identification in standard solution and serum samples

The applicability of a trypsin-based monolithic bioreactor coupled on-line with LC/MS/MS for rapid
proteolytic digestion and protein identification is here described. Dilute samples are passed through
the bioreactor for generation of proteolytic fragments in less than 10 min. After digestion and peptide
separation, electrospray ionization tandem mass spectrometry is used to generate a peptide map and
to identify proteolytic peptides by correlating their fragmentation spectra with amino acid sequences
from a protein database. By digesting picomoles of proteins sufficient data from ESI and MS/MS were
obtained to unambiguously identify proteins alone and in serum samples. This approach was also
extended to locate mutation sites in beta-lactoglobulin A and B variants.