Purification and characterization of subcomponent C1q of the first component of mouse complement.
1. Mouse C1q, a subcomponent of the first component of complement, has been purified in a highly haemolytically active form by a combination of precipitation with EGTA, ion-exchange chromatography and gel filtration. Yields ranged from 3 to 5 mg/200 ml of serum, and the activity of final preparations was in the range of 2 X 10(13)-4 X 10(13) C1q effective molecules/mg. 2. The molecular weight of mouse C1q was 439 500 +/- 1586, as determined by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. 3. Mouse C1q was shown to be composed of non-covalently linked subunits, all being in the molecular-weight range 45 000-46 000, and three covalently linked chains each having a molecular weight of approx. 23 000 as determined on polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate by using non-covalently and covalently linked subunits of human C1q as markers with known molecular weights calculated theoretically previously [Porter & Reid (1978) Nature (London) 275, 699-704]. 4. Mouse C1q contained hydroxyproline, hydroxylysine, a high percentage of glycine and approx. 9% carbohydrate. The absorption coefficient and nitrogen content of C1q were also determined.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003172:Complement C1 / Q000276:immunology / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D008297:Male; D051379:Mice / Q000276:immunology*; D008970:Molecular Weight
D000596:Amino Acids; D002241:Carbohydrates; D003172:Complement C1