Immobilized pepsin microreactor for rapid peptide mapping with nanoelectrospray ionization mass spectrometry.
Most enzymatic microreactors for protein digestion are based on trypsin, but proteins with hydrophobic segments may be difficult to digest because of the paucity of Arg and Lys residues. Microreactors based on pepsin, which is less specific than trypsin, can overcome this challenge. Here, an integrated immobilized pepsin microreactor (IPMR)/nanoelectrospray emitter is examined for its potential for peptide mapping. For myoglobin, equivalent sequence coverage is obtained in a thousandth the time of solution digestion with better sequence coverage. While sequence coverage of cytochrome c is lesser than solution in this short duration, more highly-charged peptic peptides are produced and a number of peaks are unidentified at low-resolution, suggesting that high-resolution mass spectrometry is needed to take full advantage of integrated IPMR/nanoelectrospray devices.
Department of Chemistry, Natural Sciences Complex, University at Buffalo, State University of New York, Buffalo, NY, 14260-3000, USA.
Ying
Y
Long
Troy D
TD
Wood
D000595:Amino Acid Sequence; D000818:Animals; D019149:Bioreactors; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D006736:Horses; D008969:Molecular Sequence Data; D036103:Nanotechnology / Q000379:methods*; D010434:Pepsin A / Q000737:chemistry / Q000378:metabolism*; D010446:Peptide Fragments / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D010449:Peptide Mapping / Q000379:methods*; D011506:Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013552:Swine
D004800:Enzymes, Immobilized; D010446:Peptide Fragments; D011506:Proteins; D010434:Pepsin A