Characterisation and purification of some glycoproteins by high-performance liquid chromatography

Native and desialylated human chorionic gonadotrophin showed different elution profiles by size-exclusion high-performance liquid chromatography (HPLC) and the difference was more pronounced using a mobile phase of low ionic strength. Ion-pair reversed-phase HPLC separated components of human chorionic gonadotrophin with apparent molecular weights ranging from 14,000 to 58,000 daltons (using sodium dodecyl sulphate gel electrophoresis). An affinity support prepared by attaching serotonin to LiChrosorb Diol specifically bound components containing sialic acid and may be useful for purification of sialoglycoproteins such as the glycoprotein hormones, beta-interferon and transferrin. Size-exclusion HPLC revealed that of two human luteinizing hormone preparations whose sialic acid content correlated with their published in vivo activities, that with higher in vivo activity contained a significant quantity of high-molecular-weight material (possibly aggregation) which was not evident in the sample of lower potency.