title: A murine C4 molecule with reduced hemolytic efficiency.
abstract: C4 functional activity and antigenic levels were determined in H-2-congenic mouse strains. In strains with the H-2w7 haplotype, the C4 hemolytic activity per unit of residual Ss antigenic activity, after depletion of the nonfunctional Slp-positive molecules was 25-33% that found with other H-2 haplotypes. This reduced hemolytic efficiency was not the result of either a more labile C4 molecule or of the presence of inhibitors. Moreover, other strains with comparable antigenic concentrations of Ss (C4) and Slp has three- to fourfold higher levels of C4 hemolytic activity. Based on these data and previously reported structural differences between C4 molecules from the H-2w7 haplotype compared with other standard H-2 haplotypes, the reduced hemolytic efficiency of this molecule is probably secondary to alterations in the structure of its alpha-chain.
mesh_terms: D000818:Animals; D000941:Antigens; D001798:Blood Proteins / Q000276:immunology; D003181:Complement C4 / Q000502:physiology*; D006183:H-2 Antigens; D006461:Hemolysis; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D011487:Protein Conformation
chemical_list: D000941:Antigens; D001798:Blood Proteins; D003181:Complement C4; D006183:H-2 Antigens