Primary structure of human class II histocompatibility antigens. Reversed-phase high-performance liquid chromatography for integral membrane proteins.
The amino acid sequence of the human HLA-DR2 class II antigen was determined with the aid of high-performance liquid chromatography. By applying exclusively Hypersil-ODS as the stationary phase in combination with three buffer systems, the amino acid sequences of the extracellular parts of the DR alpha- and DR beta-chains could be established. Moreover, the sensitivity of the procedure allowed the determination of the primary structures of additional class II polypeptides isolated together with the DR2 alpha- and the DR2 beta-chains. Significant insight into the heterogeneity of class II molecules was thereby obtained. In addition, a simple, rapid and selective method of general applicability is described for the isolation of membrane fragments of integral membrane proteins. Using Sep-Pak cartridges with a mobile phase containing 60% formic acid and varying 1-propanol concentrations, the highly hydrophobic peptides can selectively be separated from the hydrophilic fragments.
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D006801:Humans; D006868:Hydrolysis; D007525:Isoelectric Focusing; D008565:Membrane Proteins / Q000032:analysis*; D010455:Peptides / Q000032:analysis
D000596:Amino Acids; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D008565:Membrane Proteins; D010455:Peptides