title: The third complement factor (C3) and its in vivo cleavage products: interaction with lectins and precipitation with polyethylene glycol.
abstract: Five molecular forms of C3 expressing D but not C epitopes were identified following in vivo activation of the complement system. Examination of concanavalin A (Con-A) reactivity in crossed immunoelectrophoresis revealed that native C3, C3c and the beta mobile form 4 of C3d were completely precipitated by 100 micrograms Con A/cm2. The alpha-1 mobile form 1 of C3d did not interact with Con A, whereas the alpha-2 mobile forms 2 and 3 were retarded in electrophoretic migration by Con A. Native C3, C3c, and forms 4 and 5 of C3d were precipitated by 12% (w/v) polyethylene glycol (PEG). Form 1 of C3d was soluble in these PEG concentrations, whereas forms 2 and 3 were partially precipitated.
mesh_terms: D000937:Antigen-Antibody Reactions; D011232:Chemical Precipitation; D003176:Complement C3 / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D015932:Complement C3c; D015933:Complement C3d; D004347:Drug Interactions; D006801:Humans; D007123:Immunoelectrophoresis, Two-Dimensional; D037102:Lectins / Q000276:immunology*; D011092:Polyethylene Glycols
chemical_list: D003176:Complement C3; D037102:Lectins; D011092:Polyethylene Glycols; D015932:Complement C3c; D015933:Complement C3d