Analysis of the Saccharomyces spindle pole by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry - PubMed (original) (raw)
Identification of the proteins Kar3p, Spc72p, and Nup85p in band 2k by MALDI peptide mass mapping and iterative database searching using a peptide mass error of less than 30 ppm. Asterisk, matrix or trypsin autolysis peaks used as internal calibration peaks; inset, data quality obtained for the ion signal at m/z 1960, mass resolution of 10,000 (full width at half maximum) allowed monoisotopic mass determination with a mass error of only 11 ppm. The measured masses (monoisotopic protonated peptide molecular weight) of the three proteins identified together with the deviations from the matched mass and any amino acid modifications in brackets were as follows: Kar3p: 992.627 (0.027), 1077.628 (−0.002), 1170.580 (0.034), 1178.627 (0.010), 1248.654 (0.011), 1252.675 (0.011), 1272.706 (−0.010), 1284.643 (−0.005, methionine sulphoxide), 1314.669 (−0.011), 1475.793 (−0.013), 1498.724 (0.014, methionine sulphoxide), 1513.832 (0.021), 1568.788 (0.029), 1610.862 (−0.003), 1626.839 (0.033, methionine sulphoxide), 1704.891 (0.021), 1945.031 (−0.004), 1960.951 (−0.021), 1997.982 (−0.014), 2057.999 (0.011), 2253.089 (−0.033), 2476.233 (−0.017, methionine sulphoxide); Yal047p/ Spc72p: 939.571 (0.009), 943.592 (−0.001), 1187.635 (−0.003), 1188.617 (0.032), 1196.685 (0.018), 1218.662 (−0.025), 1246.659 (−0.020), 1406.755 (0.028), 1429.754 (−0.010), 1437.828 (−0.018), 1486.812 (0.001), 1534.814 (−0.008), 1635.867 (−0.022), 2036.030 (0.037), 2087.030 (0.004), 2613.342 (0.053); Nup85p: 1147.631 (−0.008), 1383.750 (−0.006), 1399.740 (0.018), 1653.830 (−0.037), 1680.841 (0.014), 1705.901 (−0.026), 1738.873 (0.012), 1751.876 (−0.020), 1885.920 (−0.016), 1898.983 (−0.018), 1899.954 (0.002, S-acrylamidocysteine), 1934.916 (−0.049). The particular peptides identified in each protein can be obtained by entering the measured masses into the PeptideSearch software available at