A new, simplified method for oxidation of human complement component C2.

C M Brickman; J P Atherton; N L Kantor

doi:10.1016/0022-1759(90)90025-q

Home/Archive/PubMed

PubMed · 2170532

A new, simplified method for oxidation of human complement component C2.

C M Brickman·J P Atherton·N L Kantor

View original source ↗Export metadata ↓

Abstract

Oxy C2 is a valuable immunologic reagent, particularly for investigators whose research or clinical assays require a stable classical pathway C3 and/or C5 convertase or a highly active plasma complement source. To date only one method for the conversion of serum C2 or purified C2 to their respective oxy C2 forms has been published. However, this method has several disadvantages. For example, handling and dissolving the iodine crystals required in this process are difficult and time consuming. Also, the enhancement procedure results in a significant dilution of the original C2 sample. We have, therefore, developed a new, simplified method for oxidation of plasma, serum, or pure C2 which circumvents the difficulties associated with the earlier method. Moreover, this method offers additional flexibility with regard to oxidative conditions (i.e., buffer pH, temperature, and C2 concentrations) and reagent handling and final C2 product stability.

Explore related subjects

Complement C2 Humans Hydrogen-Ion Concentration Hypochlorous Acid In Vitro Techniques Oxidation-Reduction Plasma Potassium Iodide Journal Article

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

C M Brickman, J P Atherton, N L Kantor. 1990-09-14. A new, simplified method for oxidation of human complement component C2.. https://doi.org/10.1016/0022-1759(90)90025-q

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1992

Modulation of C2 and C3 gene expression of human peripheral blood monocytes by interleukin 1 beta, interferon gamma, tumor necrosis factor alpha and lipopolysaccharide.

The effect of interleukin 1 beta (IL-1 beta), interferon gamma (IFN-gamma), tumor necrosis factor alpha (TNF alpha) and lipopolysaccharide (LPS) on the expression of the C2 and C3 genes in human adherent monocytes was studied. Stimulation of monocytes with IFN-gamma increased both C2 and C3 mRNA. IL-1 beta also increased C2 mRNA level, whereas C3 gene expression was not enhanced. TNF alpha failed to increase either C2 or C3 mRNA. LPS increased C2 mRNA, but suppressed C3 gene expression. These results suggest that C2 and C3 production by monocytes is regulated by IL-1 beta and IFN-gamma in the local tissues.

Complement C2↗

PubMed1992

Investigation of allotypes of HLA class III (C2, BF and C4) in patients with schizophrenia.

The allotypes of HLA Class III (C2, BF and C4) in 60 patients with schizophrenia were investigated. Significantly higher frequencies of BF*F, BF*SO7 and C4A*4 in patients were found as compared with those of the normal controls. The relative risks (RR) of the three allotypes to schizophrenia were 1.81, 7.79 and 4.18 and the etiologic fraction (EF) were 0.086, 0.060 and 0.042, respectively. There were no significant changes of C2 allotypes.

Complement C2↗

PubMed1990

Effect of sodium chloride concentration on fluid-phase assembly and stability of the C3 convertase of the classical pathway of the complement system.

The assembly of the classical-pathway C3 convertase from C4 and I2-treated C2 by the action of C1s is an Mg2(+)-dependent reaction. The Mg2+ concentration necessary for the assembly of C3 convertase in the fluid phase was found to be dependent on NaCl concentration. In the absence of NaCl more than 5 mM-MgCl2 was found to be required, whereas 0.5 mM-MgCl2 was adequate for the assembly of C3 convertase in the presence of 150 mM-NaCl. The C3 convertase assembled in a low-ionic-strength buffer was extremely labile compared with that assembled in buffer of physiological ionic strength, and the stability of C3 convertase was improved with the increase in NaCl concentration. It was found that the stabilizing effect of NaCl on C3 convertase was due to inhibition of the dissociating activity of C2b, which was formed during the assembly of C3 convertase. In addition to the dissociation-accelerating effect, C2b inhibited the assembly of C3 convertase in low-ionic-strength buffer, and this effect also was diminished with increase in NaCl concentration. An increase in NaCl concentration to more than 200 mM resulted in a decrease in the assembly of C3 convertase. This effect was not due to the lability of the assembled C3 convertase but due rather to the inhibition of C2 cleavage by C1s. Purified C3 convertase itself is stable in dilute medium or high-ionic-strength medium such as 500 mM-NaCl, suggesting that the interactions between C4b and C2a are hydrophobic. In these respects C2b seemed to be functionally similar to C4bp, but C2b failed to act as a cofactor for the Factor I-catalysed C4b cleavage.

Complement C2↗