Isolation and characterization of highly stable rabbit C1q.
Rabbit C1q has been isolated by techniques which retain elements of previous isolation methods along with novel procedures incorporated to yield stable, non-aggregating, highly purified and biologically active C1q. The procedure involves euglobulin preparation by dialysis of serum and two column chromatographies, DEAE-Sephadex and Ultragel ACA 34. The method results in yields of C1q from rabbit sera of 20-30%. Ouchterlony analysis, sedimentation velocity experiments, equilibrium ultracentrifuge molecular weight analysis, SDS, polyacrylamide gel electrophoresis and isoelectric focusing experiments indicate the presence of only a single component, which has all the physical characteristics previously reported for C1q. The preparation has all the biological characteristics of C1q such as the ability to agglutinate IgG-coated latex particles and to restore hemolytic activity to RC1q serum. Preparations obtained by this procedure are stable to freezing (-70 degrees C) for extended periods of time and show no evidence of aggregation upon thawing following periods of storage of up to 6 months. Mild acetylation and handling of preparations for extended periods at 37 degrees C and 45 degrees C indicate no evidence of aggregation or loss of agglutinating and hemolytic activities. Preparations so isolated meet all the criteria required for critical physical-chemical studies of this protein.
D000818:Animals; D002852:Chromatography, Ion Exchange; D003172:Complement C1 / Q000302:isolation & purification* / Q000378:metabolism; D005782:Gels; D007525:Isoelectric Focusing; D008722:Methods; D011817:Rabbits; D013997:Time Factors
D003172:Complement C1; D005782:Gels