Nanoscale liquid chromatography-electrospray ionization

This protocol describes a procedure for the identification of PTM by HNE to reveal protein targets and specific sites of covalent attachment. Identification is performed by combining proteolytic digestion followed by SPH enrichment and nanoscale liquid chromatography-electrospray ionization tandem mass spectrometry (nano-LC-ESI-MS/MS).The modified proteins are subjected to reduction, alkylation, and subsequent digestion by a proteolytic enzyme. The peptides thus obtained are desalted and the substoichiometric quantities of HNE-modified peptides are fractionated from unmodified species using hydrazide-coated glass beads-based enrichment technique that selectively captures peptide carbonyls (as hydrazones) that are subsequently... 

Parker, C.E. Perkins, J.R. Tomer, K.B. Shida, Y. O Heu-a, K. Nanoscale packed capillary liquid chromatography-electrospray ionization mass spectrometry analysis of penicillins and cephems. J.Chromatogr., 1993, 616, 45-57 [capillary HPLC electrospray LC-MS serum also ampiciUin, car-benicUlin, cefalothin, cefazoUn, cefmenoxime, cefmetetzole, cefoperazone, cefotaxime, cefotiam, cefoxitin, cephalexin, cloxacillin, dicloxacillin, peniciUin G, pipericillin, sulbenicillin]... 

Bile acids, alcohols, and side-chain-shortened steroids have been extensively analyzed by liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS) [1-3].The mobile phase usually features water/ methanol or water/acetonitrile containing an organic acid or buffer. As ESI is a concentration-dependent process, maximum sensitivity is obtained with high-concentration, low-volume samples run at low flow rate [26,27]. We have extensively used low-flow-rate LC-ESI-MS to achieve maximum sensitivity for steroid analysis [26], and with the advent of reliable nanoscale liquid chromatography (nano-LC) equipment, this form... 

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