Interaction between complement subcomponent C1q and bacterial lipopolysaccharides

Interaction between complement subcomponent C1q and bacterial lipopolysaccharides.

The heptose-less mutant of Escherichia coli, D31m4, bound complement subcomponent C1q and its collagen-like fragments (C1qCLF) with Ka values of 1.4 x 10(8) and 2.0 x 10(8) M-1 respectively. This binding was suppressed by chemical modification of C1q and C1qCLF using diethyl pyrocarbonate (DEPC). To investigate the role of lipopolysaccharides (LPS) in this binding, biosynthetically labelled [14...

Separation of hydroxyproline-containing protein from C1q (a subcomponent of complement) in serum.

Precipitation of the euglobulin fraction from serum separates C1q from another hydroxyproline-containing protein(s), which remains in the serum-minus-euglobulin fraction. The presence of C1q in the euglobulin fraction has been verified by radial immunodiffusion assay, by sensitivity to collagenase, by hydroxyproline content, and by electrofocusing. The presence of another hydroxyproline-contain...

Complement C 1 q subcomponent subunit A

Isolation and characterization of C1q, a subcomponent of the first component of complement, from human and rabbit sera.

1. C1q, a subcomponent of the first component of complement, has been isolated, in a haemolytically active and soluble form, by ion-exchange chromatography and gel filtration, from human and rabbit sera. Yields ranged from 10 to 25mg/litre of serum and the activity of final preparations was consistently in the range 5x10(3)-15x10(3) C1qH(50) units/mg. 2. The molecular weights of human and rabbi...

Complement, C1q, and C1q-Related Molecules Regulate Macrophage Polarization

Complement is a critical system of enzymes, regulatory proteins, and receptors that regulates both innate and adaptive immune responses. Natural mutations in complement molecules highlight their requirement in regulation of a variety of human conditions including infectious disease and autoimmunity. As sentinels of the immune system, macrophages are specialized to respond to infectious microbes...