We present evidence suggesting that nonenzymatic, spontaneous hydrolysis of a thioester bond in native C3 constitutes the initial event in the activation of the alternative pathway. It has been known since the original description of C3 that the hemolytic activity of the isolated protein decays spontaneously in aqueous solution at a slow rate (1). This decay was greatly accelerated by chaotropi...

Herein we report directed iridium-catalyzed C3−H silylation of furfuryl imines, which grants access to versatile synthetic platforms. This transformation was developed on derivatives, using imines as directing groups, and trialkylsilanes or bis(trimethylsilyl)methylsilane silylating agents, in the presence a hydride scavenger. Subsequently, fluoride-mediated activation strategies were applied C...

BACKGROUND It has been reported that three common loci, SstI, C-482T, and T-455C, in the apolipoprotein C3 (APOC3) gene might be associated with an increased risk of coronary heart disease (CHD). Considering the inconsistent results and ethnicity variations, we performed a systematic meta-analysis to evaluate the association between three single nucleotide polymorphisms (SNPs) and the risk of C...

BACKGROUND Clinical assessment and prognostic stratification of primary varicose veins have remained controversial and the molecular pathogenesis is unknown. Previous data have suggested a contribution of the MTHFR (methylenetetrahydrofolate reductase) polymorphism c.677C>T. METHODS We collected blood and vein specimens from 159 consecutive patients undergoing varicose vein surgery, or autolo...

We examined the interaction of complement component C3 with surface molecules on Trypanosoma cruzi. Five- to six-fold more C3 was bound to epimastigotes (Epi) than to metacyclic trypomastigotes (CMT) of strain M88. Epi and CMT were surface iodinated, then incubated in C8-deficient serum, and detergent lysates were applied to anti-C3 antibody that had been coupled to Sepharose. We found that 9.2...

Two complex enzymes were assembled that both converted C3 to C3b, one consisting of activated properdin (P), native C3, proactivator (PA) and proactivator convertase (PAase), and the other of nephritic factor (NF) and the same three cofactors. By maintaining a critical concentration of PAase, the P-C3 convertase and the NF-C3 convertase were shown to function efficiently without formation of th...

C3-bearing immune complexes and C3 activation products were detected by using two monoclonal antibodies, one specific for a neoantigenic determinant on C3c and the other for C3d. To quantitate immune complexes, the anti-C3c or anti-C3d antibodies were fixed to microtiter plates and reacted with test plasma. The binding of C3-bearing immune complexes in this plasma was then measured with radiois...

OBJECTIVE For the inflammation characteristic of rheumatoid arthritis, the relative contribution of mediators produced locally in the synovium versus those circulating systemically is unknown. Complement factor C3 is made in rheumatoid synovium and has been proposed to be a crucial driver of inflammation. The aim of this study was to test, in a mouse model of rheumatoid arthritis, whether C3 sy...