Characterization of Clq, Cls and Cl̄ Inh synthesized by stimulated human monocytes in vitro

Abstract Clq, Cls and Cl Inh synthesized and secreted by human monocytes were characterized by SDS-PAGE. Clq is formed of three chains A ( M r ~35000), B ( M r ~33000) and C ( M r ~25000) which are associated in two subunits A-B and C-C. It appears identical to C1q purified from plasma. Cls is secreted as a non-activated, monocatenar protein of M r ~87000 identical to proenzymic Cls from plasma. Secreted Cl Inh ( M r ~100000) has a slightly higher M r than purified plasmatic Cl Inh. Monensin treatment of the cells favours the intracytoplasmic accumulation of products at various glycosylation stages.