title: Change of electrophoretic mobility of purified alternative pathway factor D.
abstract: The electrophoretic mobility of factor D (D) of the alternative pathway of human complement activation was examined by the method of lysoelectrophoresis. Purified D was found to have beta-mobility, while D in fresh serum showed alpha-mobility. Addition of D-depleted serum to D induced a change of electrophoretic mobility from beta to alpha. Addition of guinea pig serum to D did not produce this change. The change of electrophoretic mobility of D was not due to complex formation between D and other known alternative factors, P, C3NeF, B and C3. The Factor(s), which mediated the change in the electrophoretic mobility of D, had pseudoglobulin properties and was distributed around the third peak on Sephadex G-200 gel filtration of human serum with a mol. wt. of 50,000-80,000. This phenomenon might be restricted to a semi-solid state reaction, because complexes containing D were not observed upon analyses by sucrose density gradient ultracentrifugation and isoelectrofocusing.
mesh_terms: D000818:Animals; D003166:Complement Activating Enzymes / Q000378:metabolism*; D011415:Complement Factor B / Q000378:metabolism; D011416:Complement Factor D / Q000302:isolation & purification / Q000378:metabolism*; D004347:Drug Interactions; D004586:Electrophoresis; D006168:Guinea Pigs; D006801:Humans; D007106:Immune Sera; D007525:Isoelectric Focusing; D014461:Ultracentrifugation
chemical_list: D007106:Immune Sera; D003166:Complement Activating Enzymes; C493488:CFD protein, human; D011416:Complement Factor D; D011415:Complement Factor B