Determination of molecular weights of C hordeins by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS)

The molecular weights of nine C hordein proteins, including all of the major components identified by SDS-PAGE have been determined by MALDI-MS. Most were in the range 43,561 to 46,857, with a single component of M_r 57,606. These are higher than the masses previously reported based on the sequences of cloned genes. This indicates that reliance on masses determined solely by gene sequencing is not valid, presumably because these may not encode the major expressed proteins.