PEPTIDE-MASS PROFILES OF POLYVINYLIDENE DIFLUORIDE-BOUND PROTEINS BY MATRIX-ASSISTED LASER-DESORPTION IONIZATION TIME-OF-FLIGHT MASS-SPECTROMETRY IN THE PRESENCE OF NONIONIC DETERGENTS

Matrix-assisted laser desorption/ionization time-of-flight mass spectr ometry (MALDI-TOF MS), in conjunction with enzymatic digestion of prot eins and molecular weight search of peptide-mass database is a powerfu l technique for peptide/protein identification. Ideally, peptide mixtu res should be compatible with both MALDI-TOF and microsequencing. In o ur laboratory, enzymatic digestion and extraction of peptides from pol yvinylidene difluoride (PVDF)bound proteins is performed in the presen ce of nonionic detergents. However, nonionic detergents have been show n to cause signal suppression in MALDI-TOF analysis. This study demons trates that by using a modified matrix solution, peptide-mass fingerpr inting of PVDF-bound proteins by MALDI-TOF can be obtained in the pres ence of nonionic detergents such as hydrogenated Triton X-100 (RTX-100 ), octylglucopyranoside, and Tween 20. (C) 1996 Academic Press, Inc.