Amino acid sequence analysis of the glycopeptides from human complement component C3.
Human complement component C3 has been cleaved completely by trypsin in the presence of 2-propanol. The hydrolysate was fully solubilized and fractionated by reversed-phase HPLC. Two peptides only contained glucosamine, Unambiguous sequence analyses identified Asn-63 of the beta-chain and Asn-268 of the alpha-chain as the sites of carbohydrate attachment. A third potential Asn-Xaa-Thr/Ser glycosylation site, Asn-946 of the alpha-chain, is not modified. The different states of glycosylation of the sites cannot be explained by differences in exposure or secondary structure. All three are predicted reverse turn.
D000433:1-Propanol; D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D003176:Complement C3 / Q000032:analysis*; D006020:Glycopeptides / Q000032:analysis*; D006801:Humans; D006868:Hydrolysis; D010434:Pepsin A; D013820:Thermolysin; D014357:Trypsin
D003176:Complement C3; D006020:Glycopeptides; D000433:1-Propanol; D014357:Trypsin; D010434:Pepsin A; D013820:Thermolysin