title: Partial characterization of human complement factor H by protein and cDNA sequencing: homology with other complement and non-complement proteins.
abstract: Factor H, a control protein of the human complement system, is closely related in functional activity to two other complement control proteins, C4b-binding protein (C4bp) and complement receptor type 1 (CR1). C4bp is known to have an unusual primary structure consisting of eight homologous units each about 60 amino acids long. Such units also occur in the N-terminal regions of the complement proteins C2 and factor B, and in the non-complement serum glycoprotein beta 2I. Amino acid sequencing, and sequencing of a factor H cDNA clone, show that factor H also contains internal repeating units, and is homologous to the proteins listed above.
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular / Q000379:methods; D003101:Collodion; D003180:Complement C3b Inactivator Proteins / Q000302:isolation & purification* / Q000502:physiology; D017242:Complement Factor H; D004247:DNA; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D010209:Paper; D012333:RNA, Messenger / Q000032:analysis; D012689:Sequence Homology, Nucleic Acid
chemical_list: C493495:CFH protein, human; D003180:Complement C3b Inactivator Proteins; D012333:RNA, Messenger; D017242:Complement Factor H; D003101:Collodion; D004247:DNA