title: Expression of functional human C1 inhibitor in COS cells.
abstract: Full length human C1 inhibitor cDNA was cloned into a vector suitable for transient expression in COS-1 cells. Transfected COS cells secreted an immunoreactive protein of Mr approximately 110,000 that appeared to be functionally equivalent to the plasma-derived protein as established by the following criteria: 1) ability to form sodium dodecyl sulfate-stable complexes with C1s, factor XIIa, and kallikrein; 2) inhibition of C1s-mediated C4 consumption; and 3) susceptibility to inactivation by the nontarget proteinase elastase. Quantitation of secreted recombinant C1 inhibitor by radioimmunoassay indicated that 72 h after transfection the level was approximately 2.2 micrograms/ml. Treatment of transfected cells with tunicamycin resulted in secretion of a protein of Mr approximately 90,000 that was also capable of complex formation with C1s.
authors.affiliation: Central Laboratory, Netherlands Red Cross Blood Transfusion Service, Amsterdam.
authors.forename: E
authors.initials: E
authors.lastname: Eldering
authors.forename: J H
authors.initials: JH
authors.lastname: Nuijens
authors.forename: C E
authors.initials: CE
authors.lastname: Hack
mesh_terms: D000818:Animals; D002460:Cell Line; D003174:Complement C1 Inactivator Proteins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D003173:Complement C1s / Q000378:metabolism; D003181:Complement C4 / Q000378:metabolism; D004247:DNA / Q000235:genetics; D004274:DNA, Recombinant; D004591:Electrophoresis, Polyacrylamide Gel; D005174:Factor XII / Q000378:metabolism; D015956:Factor XIIa; D000882:Haplorhini; D006801:Humans; D007118:Immunoassay; D007610:Kallikreins / Q000378:metabolism; D010196:Pancreatic Elastase / Q000494:pharmacology; D011994:Recombinant Proteins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D012697:Serine Endopeptidases / Q000378:metabolism; D013539:Simian virus 40 / Q000235:genetics; D014158:Transcription, Genetic; D014162:Transfection; D014415:Tunicamycin / Q000494:pharmacology
chemical_list: D003174:Complement C1 Inactivator Proteins; D003181:Complement C4; D004274:DNA, Recombinant; D011994:Recombinant Proteins; D014415:Tunicamycin; D005174:Factor XII; D004247:DNA; D007610:Kallikreins; D012697:Serine Endopeptidases; D010196:Pancreatic Elastase; D015956:Factor XIIa; D003173:Complement C1s