Cell-free synthesis of the fourth component of guinea pig complement (C4): identification of a precursor of serum C4 (pro-C4).

Cell-free synthesis of the fourth component of guinea pig complement (C4): identification of a precursor of serum C4 (pro-C4).

Polysomes (S-20) from homogenates of guinea pig liver synthesized serum albumin and a precursor of the fourth component of guinea pig complement (C4) in vitro. The C4 precursor (pro-C4) accounted for approximately 0.2% and albumin 4% of the radiolabeled protein precipitable by trichloroacetic acid and not bound to polysomes. Pro-C4 is a single polypeptide chain (molecular weight 200,000) which ...

The complement component C4 of mammals.

Human complement component C4 is coded by tandem genes located in the HLA class III region. The products of the two genes, C4A and C4B, are different in their activity. This difference is due to a degree of 'substrate' specificity in the covalent binding reactions of the two isotypes. Mouse also has a duplicated locus, but only one gene produces active C4, while the other codes for the closely ...

The purification and characterization of bovine C4, the fourth component of complement.

The fourth component of complement, C4, was isolated from bovine plasma in high yield, by using simple purification techniques. The protein, like human component C4, is a beta-globulin with a mol.wt. of about 200 000 and consists of three polypeptide chains, alpha, beta and gamma, with apparent mol. wts. of 98 000, 82 000 and 32 000 respectively. The chains of C4 have been separated by methods ...

TaqI RFLP polymorphism of the ovine complement component C4 gene.

Protocol: Reactions were performed as described (2) using 1 ng of DNA and 100 pmoles of each primer. DNA was amplified for 20 cycles using a Perkin Elmer Cetus DNA Thermal Cycler: denaturation, 94°C, 1 min; annealing, 60°C, 1 min; and extension, 70°C, 1.5 min. Ten /il of the reaction was analyzed directly on a 2.5 % NuSieve GTG agarose gel run in Tns-borate buffer. The amplified DNA fragments v...

Immunity in C4-Deficient Mice Component C4 Can Restore Humoral Macrophage-Derived Complement