title: Isolation of two molecular populations of human complement factor H by hydrophobic affinity chromatography.
abstract: Human complement factor H was prepared in highly purified form from fresh serum by euglobulin precipitation, DEAE-Sephacel chromatography and Sephacryl S-300 gel filtration. This preparation allowed the recovery of 37% of the initial factor H. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis revealed that factor H was homogeneous both in reduced and non-reduced media and exhibited a molecular mass of 150 kDa. Charge-shift experiments clearly showed the presence of hydrophobic sites in the factor H molecule. Charge shifts were observed with two detergent systems (Triton/sodium deoxycholate and Triton/cetyltrimethylammonium bromide). Factor H was able to bind to phenyl-Sepharose. This property allowed us to study two populations of factor H. These two populations exhibited the same physicochemical parameters, but revealed differences in their ability to aggregate in low- and iso-ionic-strength media. The molecular basis and biological significance of this heterogeneity are discussed.
mesh_terms: D000595:Amino Acid Sequence; D011232:Chemical Precipitation; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003179:Complement C3b; D003180:Complement C3b Inactivator Proteins / Q000302:isolation & purification*; D017242:Complement Factor H; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D046911:Macromolecular Substances; D008970:Molecular Weight; D009994:Osmolar Concentration; D012712:Serum Globulins
chemical_list: C493495:CFH protein, human; D003180:Complement C3b Inactivator Proteins; D046911:Macromolecular Substances; D012712:Serum Globulins; D003179:Complement C3b; D017242:Complement Factor H