title: Use of a high-efficiency expression vector to isolate cDNA clones for factor H and map their positions within the molecule.
abstract: A human liver cDNA library, cloned in a novel high-efficiency bacterial expression vector (PEX), was screened with an affinity-purified antibody to human factor H. Four distinct cDNA clones, H-2, H-40, H-46 and H-49, were identified. Of these, H-2 also reacted with two monoclonal antibodies to H, MAH-4 and OX-24, which were previously shown to recognize the 38,000 N-terminal tryptic fragment of H, carrying the binding site for C3b. By using polyclonal antibodies specific for the domains in H coded for by these cDNA-clones, it could be established that H-2 codes only for the 38,000 N-terminal tryptic fragment of H, whereas H-40, H-46 and H-49 are derived from the 142,000 C-terminal fragment of H. By subcloning H-2 the epitope for OX-24 could be localized as being coded near the central Sma-site of H-2.
mesh_terms: D000906:Antibodies / Q000276:immunology; D002874:Chromosome Mapping; D003180:Complement C3b Inactivator Proteins / Q000235:genetics* / Q000276:immunology; D017242:Complement Factor H; D004247:DNA / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000276:immunology; D005822:Genetic Vectors; D006801:Humans
chemical_list: D000906:Antibodies; C493495:CFH protein, human; D003180:Complement C3b Inactivator Proteins; D000939:Epitopes; D017242:Complement Factor H; D004247:DNA