title: Structure of C3f, a small peptide specifically released during inactivation of the third component of complement.
abstract: C3f, a peptide presumed to be generated by the combined actions of factors I and H on fluid-phase C3b, has been isolated and sequenced. The peptide is 17 residues long and has a molecular weight of 1,847 daltons. The amino-terminal sequence is, with the exception of a single residue, identical to that deduced for the 46-kilodalton polypeptide seen transiently in the generation of iC3b from C3b, and is in full agreement with the sequence deduced from cDNA analysis. In addition, high-pressure liquid chromatography of the digestion of C3b by factor I has shown that C3f is the sole peptide released during iC3b generation.
authors.affiliation: MITI Unit, MRC Centre, Cambridge, UK.
authors.forename: R A
authors.initials: RA
authors.lastname: Harrison
authors.forename: T C
authors.initials: TC
authors.lastname: Farries
authors.forename: F D
authors.initials: FD
authors.lastname: Northrop
authors.forename: P J
authors.initials: PJ
authors.lastname: Lachmann
authors.forename: A E
authors.initials: AE
authors.lastname: Davis
mesh_terms: D000595:Amino Acid Sequence; D003176:Complement C3 / Q000235:genetics* / Q000302:isolation & purification; D003179:Complement C3b / Q000378:metabolism; D004247:DNA / Q000235:genetics; D006801:Humans; D008970:Molecular Weight
chemical_list: D003176:Complement C3; C046821:complement C3f; D003179:Complement C3b; D004247:DNA