The ninth component of human complement: purification and physicochemical characterization.
A procedure for the isolation of the human complement (C) protein C9 is described. The procedure allowin. The purified protein has the electrophoretic mobility of an alpha-globulin, and is a single polypeptide chain with a m.w. of 71,000. No impurities were detected either on gel electrophoretic or immunochemical examination. C9 is a glycoprotein containing 7.8% carbohydrate, and in terms of residues per mole, 3.0 glucosamine, 17.6 neutral hexose, and 7.4 sialic acid. Its amino acid composition is typical of a globular serum protein. Upon automated Edman degradation of reduced and alkylated C9, no amino acid residues were released, suggesting a blocked N-terminus. The concentration of C9 in normal human serum is 58 +/- 8 microgram/ml. A high titer rabbit antiserum was produced and employed to immunochemically deplete serum of C9. The CH50 of the C9-depleted serum was identical to that of whole human serum; however, membrane fragments of erythrocytes lysed by C9-depleted serum lacked the typical ultrastructural C lesions, which constitute the dimeric membrane attack complex.
D000327:Adsorption; D000596:Amino Acids; D000818:Animals; D002241:Carbohydrates; D055598:Chemical Phenomena; D011232:Chemical Precipitation; D002627:Chemistry, Physical; D003186:Complement C9 / Q000172:deficiency / Q000302:isolation & purification*; D004591:Electrophoresis, Polyacrylamide Gel; D006461:Hemolysis; D006801:Humans; D006882:Hydroxyapatites / Q000494:pharmacology; D005779:Immunodiffusion; D008970:Molecular Weight; D010447:Peptide Hydrolases / Q000494:pharmacology; D011092:Polyethylene Glycols / Q000494:pharmacology; D011817:Rabbits
D000596:Amino Acids; D002241:Carbohydrates; D003186:Complement C9; D006882:Hydroxyapatites; D011092:Polyethylene Glycols; D010447:Peptide Hydrolases