ovalbumin and Carcinoma--Ductal--Breast

This work explores the use of 20-microm-i.d. polymeric polystyrene-divinylbenzene monolithic nanocapillary columns for the LC-ESI-MS analysis of tryptic digest peptide mixtures. In contrast to the packing of microparticles, capillary columns were prepared, without the need of high pressure, in fused-silica capillaries, by thermally induced in situ copolymerization of styrene and divinylbenzene. The polymerization conditions and mobile-phase composition were optimized for chromatographic performance leading to efficiencies over 100000 plates/m for peptide separations. High mass sensitivity (approximately 10 amol of peptides) in the MS and MS/MS modes using an ion trap MS was found, a factor of up to 20-fold improvement over 75-microm-i.d. nanocolumns. A wide linear dynamic range (approximately 4 orders of magnitude) was achieved, and good run-to-run and column-to-column reproducibility of isocratic and gradient elution separations were found. As samples, both model proteins and tissue extracts were employed. Gradient nano-LC-MS analysis of a proteolytic digest of a tissue extract, equivalent to a sample size of approximately 1000 cells injected, is presented.

Topics: Amino Acid Sequence; Animals; Carcinoma, Ductal, Breast; Caseins; Catalase; Cattle; Chickens; Chromatography, Liquid; Cytochromes c; Databases, Protein; Female; Horses; Humans; Lactoglobulins; Microscopy, Electron, Scanning; Molecular Sequence Data; Myoglobin; Neuropeptides; Ovalbumin; Peptide Fragments; Polystyrenes; Proteins; Reproducibility of Results; Spectrometry, Mass, Electrospray Ionization; Tissue Extracts; Trypsin; Trypsinogen