Quantitative Determination of Saccharide Surfactants in Protein Samples by Liquid Chromatography Coupled to Electrospray Ionization Mass Spectrometry

✍ Scribed by Gejing Deng; Denise Chow; Gautam Sanyal

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 92 KB
• Volume: 289
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1006/abio.2000.4939

✦ Synopsis

A direct and highly selective method, combining liquid chromatography (LC) with electrospray ionization mass spectrometry (ESI-MS), has been developed for quantifying saccharide surfactants. Saccharide surfactants, such as n-octyl-beta-d-glucopyranoside (NOG), are widely used to solubilize or refold membrane-bound or lipophilic proteins. In the present study, we have developed an LC-MS method to quantify NOG in protein samples. Protein-bound NOG was completely dissociated from proteins by reversed-phase LC, allowing the total amount of saccharide surfactant in protein samples to be quantified by MS. A chemical analog of NOG was used as an internal standard for improving the reproducibility of the method. Linearity was found in the range of 10 microg/mL-1.0 mg/mL NOG concentrations. Seven major surfactant oligomeric ions were detected under the ionization conditions applied and their relative abundance was essentially unchanged over the range of 0.05-1.0 mg/mL NOG concentrations. Consequently, ions with characteristic mass-to-charge ratios could be used for quantification of NOG. Analytical accuracy of the method was examined by determining the amounts of NOG recovered from apolipoprotein A-I and myoglobin samples spiked with NOG.