ANALYSIS OF NEUTRAL SUGARS BY GAS-LIQUID CHROMATOGRAPHY OF ALDITOL ACETATES - APPLICATION TO THYROTROPIC HORMONE AND OTHER GLYCOPROTEINS

A method was developed for the quantitative determination of the neutral sugars of several glycoproteins including thyrotropic hormone, thyroglobulin, and ovalbumin by gas-liquid chromatography of alditol acetates. This approach has the advantage that only 1 peak for each sugar is present in the chromatograms, which is particularly valuable in the determination of trace components. The same samples are analyzed for hexo-samines by ion-exhcnage chromatography and the combination of methods permits analyses for all sugar components other than sialic acid on 1 or 2 milligrams of glycoprotein. In addition to the fucose and mannose previously reported, highly purified bovine thyrotropin contains approximately one-half residue of galactose per molecule with the human hormone purified by similar methods relatively richer in this sugar. Trace amounts of galactose have also been found in crystalline ovalbumin preparations further purified by chromatography.