High-performance liquid chromatography of glucagon and related compounds.
Glycerolpropylsilane bonded phases have been found to adsorb peptides and proteins via ionic interactions. In this paper high-performance liquid chromatography separation of glucagon and related compounds, using a Diol-silica matrix, is described. Crystalline, commercial preparations of glucagon, when analyzed on LiChrosorb Diol columns eluted with low-ionic-strength acidic buffers, contained up to four contaminant peaks, in different numbers and ratios. Three of these contaminants, called A, C, and D, were recovered and characterized. Contaminant A, representing a few percent of the total, was a mixture of mono- and didesamidoglucagon, as shown by treatment with bis(I,I-trifluoroacetoxy)iodobenzene, with which it is possible to differentiate between carboxamide and carboxylic acid residues. Contaminant C, ranging from 0 to about 30% of the total, was N-terminal degraded glucagon. Contaminant D, ranging from a few percent to about 25% of the total, was (Met27 sulfoxide) glucagon.
D000596:Amino Acids / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003488:Cyanogen Bromide; D005934:Glucagon / Q000031:analogs & derivatives / Q000032:analysis*; D007202:Indicators and Reagents; D010084:Oxidation-Reduction; D013329:Structure-Activity Relationship
D000596:Amino Acids; D007202:Indicators and Reagents; D005934:Glucagon; D003488:Cyanogen Bromide